kth.sePublications
Change search
Refine search result
1234 101 - 150 of 189
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101.
    Bresci, Virginia
    et al.
    Sorbonne Univ, CNRS, Inst Astrophys Paris, 98 Bis Blvd Arago, F-75014 Paris, France.;CEA, DAM, DIF, F-91297 Arpajon, France..
    Lemoine, Martin
    Sorbonne Univ, CNRS, Inst Astrophys Paris, 98 Bis Blvd Arago, F-75014 Paris, France..
    Gremillet, Laurent
    CEA, DAM, DIF, F-91297 Arpajon, France.;Univ Paris Saclay, CEA, LMCE, F-91680 Bruyeres Le Chatel, France..
    Comisso, Luca
    Columbia Univ, Dept Astron, New York, NY 10027 USA.;Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA..
    Sironi, Lorenzo
    Columbia Univ, Dept Astron, New York, NY 10027 USA.;Columbia Univ, Columbia Astrophys Lab, New York, NY 10027 USA..
    Demidem, Camilia
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Hannes Alfvéns väg 12, Stockholm, SE-106 91, Sweden.
    Nonresonant particle acceleration in strong turbulence: Comparison to kinetic and MHD simulations2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 106, no 2, article id 023028Article in journal (Refereed)
    Abstract [en]

    Collisionless, magnetized turbulence offers a promising framework for the generation of nonthermal high-energy particles in various astrophysical sites. Yet, the detailed mechanism that governs particle acceleration has remained subject to debate. By means of 2D and 3D particle-in-cell, as well as 3D (incompressible) magnetohydrodynamic (MHD) simulations, we test here a recent model of nonresonant particle acceleration in strongly magnetized turbulence [Lemoine, Phys. Rev. D 104, 063020 (2021)], which ascribes the energization of particles to their continuous interaction with the random velocity flow of the turbulence, in the spirit of the original Fermi model. To do so, we compare, for a large number of particles that were tracked in the simulations, the predicted and the observed histories of particles momenta. The predicted history is that derived from the model, after extracting from the simulations, at each point along the particle trajectory, the three force terms that control acceleration: the acceleration of the field line velocity projected along the field line direction, its shear projected along the same direction, and its transverse compressive part. Overall, we find a clear correlation between the model predictions and the numerical experiments, indicating that this nonresonant model can successfully account for the bulk of particle energization through Fermi-type processes in strongly magnetized turbulence. We also observe that the parallel shear contribution tends to dominate the physics of energization in the particle-in-cell simulations, while in the magnetohydrodynamic incompressible simulation, both the parallel shear and the transverse compressive term provide about equal contributions.

  • 102.
    Buoninfante, Luca
    Nordita SU.
    Contour prescriptions in string-inspired nonlocal field theories2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 106, no 12, article id 126028Article in journal (Refereed)
    Abstract [en]

    In quantum field theory, a consistent prescription to define and deform integration contours in the complex energy plane is needed to evaluate loop integrals and compute scattering amplitudes. In some nonlocal field theories, including string field theory, interaction vertices contain transcendental functions of momenta that can diverge along certain complex directions, thus making it impossible to use standard techniques, such as Wick rotation, to perform loop integrals. The aim of this paper is to investigate the viability of several contour prescriptions in the presence of nonlocal vertices. We consider three "different" prescriptions and establish their (in)equivalence in local and nonlocal theories. In particular, we prove that all these prescriptions turn out to be equivalent in standard local theories, while this is not the case for nonlocal theories where amplitudes must be defined first in Euclidean space, and then analytically continued to Minkowski. We work at one-loop level and focus on the bubble diagram. In addition to proving general results for a large class of nonlocal theories, we show explicit calculations in a string -inspired nonlocal scalar model.

  • 103.
    Caputo, Andrea
    et al.
    Tel Aviv Univ, Sch Phys & Astron, IL-69978 Tel Aviv, Israel.;Weizmann Inst Sci, Dept Particle Phys & Astrophys, IL-7610001 Rehovot, Israel..
    Millar, Alexander J.
    Stockholm Univ, AlbaNova, Dept Phys, Oskar Klein Ctr, SE-10691 Stockholm, Sweden. NORDITA SU, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.;Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden..
    O'Hare, Ciaran A. J.
    Univ Sydney, Sch Phys, Camperdown, NSW 2006, Australia.;ARC Ctr Excellence Dark Matter Particle Phys, Camperdown, NSW 2006, Australia..
    Vitagliano, Edoardo
    Univ Calif Los Angeles, Dept Phys & Astron, Los Angeles, CA 90095 USA..
    Dark photon limits: A handbook2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 9, article id 095029Article in journal (Refereed)
    Abstract [en]

    The dark photon is a massive hypothetical particle that interacts with the Standard Model by kinetically mixing with the visible photon. For small values of the mixing parameter, dark photons can evade cosmological bounds to be a viable dark matter candidate. Due to the similarities with the electromagnetic signals generated by axions, several bounds on dark photon signals are simply reinterpretations of historical bounds set by axion haloscopes. However, the dark photon has a property that the axion does not: an intrinsic polarization. Due to the rotation of the Earth, accurately accounting for this polarization is nontrivial, highly experiment dependent, and depends upon assumptions about the dark photon's production mechanism. We show that if one does account for the dark photon polarization, and the rotation of the Earth, an experiment's discovery reach can be enhanced by over an order of magnitude. We detail the strategies that would need to be taken to properly optimize a dark photon search. These include judiciously choosing the location and orientation of the experiment, as well as strategically timing any repeated measurements. Experiments located at 135 degrees or 155 degrees latitude, making three observations at different times of the sidereal day, can achieve a sensitivity that is fully optimized and insensitive to the dark photon's polarization state, and hence its production mechanism. We also point out that several well-known searches for axions employ techniques for testing signals that preclude their ability to set exclusion limits on dark photons, and hence should not be reinterpreted as such.

  • 104.
    Carenza, Pierluca
    et al.
    The Oskar Klein Centre, Department of Physics, Stockholm University, 10691 Stockholm, Sweden.
    Sharma, Ramkishor
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. The Oskar Klein Centre, Department of Physics, Stockholm University, 10691 Stockholm, Sweden Stockholm University, Hannes Alfvéns väg 12, 10691 Stockholm, Sweden.
    Marsh, M. C.David
    The Oskar Klein Centre, Department of Physics, Stockholm University, 10691 Stockholm, Sweden.
    Brandenburg, Axel
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. The Oskar Klein Centre, Department of Physics, Stockholm University, 10691 Stockholm, Sweden; Nordita, KTH Royal Institute of Technology and Stockholm University, Hannes Alfvéns väg 12, 10691 Stockholm, Sweden; McWilliams Center for Cosmology and Department of Physics, Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213, USA; School of Natural Sciences and Medicine, Ilia State University, 3-5 Cholokashvili Avenue, 0194 Tbilisi, Georgia.
    Ravensburg, Eike
    The Oskar Klein Centre, Department of Physics, Stockholm University, 10691 Stockholm, Sweden.
    Magnetohydrodynamics predicts heavy-tailed distributions of axion-photon conversion2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 10, article id 103029Article in journal (Refereed)
    Abstract [en]

    The interconversion of axionlike particles (ALPs) and photons in magnetized astrophysical environments provides a promising route to search for ALPs. The strongest limits to date on light ALPs use galaxy clusters as ALP-photon converters. However, such studies traditionally rely on simple models of the cluster magnetic fields, with the state-of-the-art being Gaussian random fields (GRFs). We present the first systematic study of ALP-photon conversion in more realistic, turbulent fields from dedicated magnetohydrodynamic (MHD) simulations, which we compare with GRF models. For GRFs, we analytically derive the distribution of conversion ratios at fixed energy and find that it follows an exponential law. We find that the MHD models agree with the exponential law for typical, small-amplitude mixings but exhibit distinctly heavy tails for rare and large mixings. We explain how non-Gaussian features, e.g., coherent structures and local spikes in the MHD magnetic field, are responsible for the heavy tail. Our results suggest that limits placed on ALPs using GRFs are robust.

  • 105.
    Caribé, João G.A.
    et al.
    Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, CEP 22290-180, Brazil.
    Jonsson, Robert H.
    Nordita SU; Max Planck Institute of Quantum Optics, Hans-Kopfermann-Str. 1, 85748 Garching, Germany, Hans-Kopfermann-Str. 1.
    Casals, Marc
    Centro Brasileiro de Pesquisas Físicas (CBPF), Rio de Janeiro, CEP 22290-180, Brazil; Institut für Theoretische Physik, Universität Leipzig, Brüderstraße 16, 04103 Leipzig, Germany, Brüderstraße 16; School of Mathematics and Statistics, University College Dublin, Belfield, Dublin 4, Ireland, Belfield, 4; Laboratoire Univers et Théories, Observatoire de Paris, CNRS, Université PSL, Université de Paris, 92190 Meudon, France.
    Kempf, Achim
    Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada; Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 Canada; Perimeter Institute for Theoretical Physics, 31 Caroline St N, Waterloo, Ontario, N2L 2Y5, Canada, 31 Caroline St N; Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
    Martín-Martínez, Eduardo
    Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada; Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, N2L 3G1 Canada; Perimeter Institute for Theoretical Physics, 31 Caroline St N, Waterloo, Ontario, N2L 2Y5, Canada, 31 Caroline St N; Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
    Lensing of vacuum entanglement near Schwarzschild black holes2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 2, article id 025016Article in journal (Refereed)
    Abstract [en]

    An important feature of Schwarzschild spacetime is the presence of orbiting null geodesics and caustics. Their presence implies strong gravitational lensing effects for matter and radiation, i.e., for excitations of quantum fields. Here, we raise the question whether the lensing manifests itself also in the vacuum of quantum fields, namely by lensing the distribution of vacuum entanglement. To explore this possibility, we use the method of entanglement harvesting, where initially unentangled localized quantum systems are temporarily coupled to the field at different locations. We find that for the Boulware, Hartle-Hawking and Unruh vacua in 3+1-dimensional Schwarzschild spacetime, the harvesting of vacuum entanglement is indeed greatly amplified near caustics. In particular, we establish that preexisting vacuum entanglement can also be harvested for lightlike separations.

  • 106. Carr, Bernard
    et al.
    Kuhnel, Florian
    KTH, School of Engineering Sciences (SCI), Physics, Theoretical Particle Physics. KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Primordial black holes with multimodal mass spectra2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 10, article id 103535Article in journal (Refereed)
    Abstract [en]

    A mechanism for generating primordial black hole mass spectra with many spikes is proposed and investigated. This mechanism relics on the choice of non-Bunch-Davies vacua, which lead to oscillatory features in the inflationary power spectrum. This in turn generates oscillations in the primordial black hole mass function with exponentially enhanced spikes. This "multimodal" effect is demonstrated for most of the well-studied models of primordial black hole formation.

  • 107.
    Chen, Hui-Huang
    et al.
    Jiangxi Normal Univ, Coll Phys & Commun Elect, Nanchang 330022, Jiangxi, Peoples R China..
    Ouyang, Hao
    Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.; Nordita SU.
    Wu, Jun-Bao
    Tianjin Univ, Ctr Joint Quantum Studies, 135 Yaguan Rd, Tianjin 300350, Peoples R China.;Tianjin Univ, Dept Phys, Sch Sci, 135 Yaguan Rd, Tianjin 300350, Peoples R China.;Peking Univ, Ctr High Energy Phys, 5 Yiheyuan Rd, Beijing 100871, Peoples R China..
    Open spin chains from determinant like operators in ABJM theory2018In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 98, no 10, article id 106012Article in journal (Refereed)
    Abstract [en]

    We study the mixing problem of the determinantlike operators in ABJM theory to two-loop order in the scalar sector. The gravity duals of these operators are open strings attached to the maximal giant graviton, which is a D4-brane wrapping a CP2 inside CP3 in our case. The anomalous dimension matrix of these operators can be regarded as an open spin chain Hamiltonian. We provide strong evidence of its integrability based on coordinate Bethe ansatz method and boundary Yang-Baxter equations.

  • 108.
    Choubey, Sandhya
    et al.
    KTH, School of Engineering Sciences (SCI), Physics. Harish-Chandra Research Institute, India.
    Dutta, Debajyoti
    Pramanik, Dipyaman
    Imprints of a light sterile neutrino at DUNE, T2HK, and T2HKK2017In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 96, no 5, article id 056026Article in journal (Refereed)
    Abstract [en]

    We evaluate the impact of sterile neutrino oscillations in the so-called 3 + 1 scenario on the proposed long baseline experiment in USA and Japan. There are two proposals for the Japan experiment which are called T2HK and T2HKK. We show the impact of sterile neutrino oscillation parameters on the expected sensitivity of T2HK and T2HKK to mass hierarchy, CP violation and octant of theta(23) and compare it against that expected in the case of standard oscillations. We add the expected ten years data from DUNE and present the combined expected sensitivity of T2HKK + DUNE to the oscillation parameters. We do a full marginalization over the relevant parameter space and show the effect of the magnitude of the true sterile mixing angles on the physics reach of these experiments. We show that if one assumes that the source of CP violation is the standard CP phase alone in the test case, then it appears that the expected CP violation sensitivity decreases due to sterile neutrinos. However, if we give up this assumption, then the CP sensitivity could go in either direction. The impact on expected octant of theta(23) and mass hierarchy sensitivity is shown to depend on the magnitude of the sterile mixing angles in a nontrivial way.

  • 109.
    Choubey, Sandhya
    et al.
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova University Center, Roslagstullsbacken 21, Stockholm, SE-106 91, Sweden.
    Ghosh, Manojit
    School of Physics, University of Hyderabad, Hyderabad, 500046, India; Center of Excellence for Advanced Materials and Sensing Devices, Ruder Bošković Institute, Zagreb, 10000, Croatia.
    Raikwal, Deepak
    Harish-Chandra Research Institute, A CI of Homi Bhabha National Institute, Chhatnag Road, Jhunsi, Prayagraj, 211019, India; Homi Bhabha National Institute, Anushakti Nagar, Mumbai, 400094, India.
    Neutrino mass ordering: Circumventing the challenges using synergy between T2HK and JUNO2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 106, no 11, article id 115013Article in journal (Refereed)
    Abstract [en]

    One of the major open problems of neutrino physics is mass ordering (MO). We discuss the prospects of measuring MO with two under-construction experiments T2HK and JUNO. JUNO alone is expected to measure MO with greater than 3σ significance as long as certain experimental challenges are met. In particular, JUNO needs better than 3% energy resolution for MO measurement. On the other hand, T2HK has rather poor prospects at measuring the MO, especially for certain ranges of the CP violating parameter δCP, posing a major drawback for T2HK. In this article we show that the synergy between JUNO and T2HK will bring twofold advantage. First, the synergy between the two experiments helps us determine the MO at a very high significance. With the baseline setup of the two experiments, we have a greater than 9σ determination of the MO for all values of δCP. Second, the synergy also allows us to relax the constraints on the two experiments. We show that JUNO could perform extremely well even for an energy resolution of 5%, while for T2HK the MO problem with "bad"values of δCP goes away. The MO sensitivity for the combined analysis is expected to be greater than 6σ for all values of δCP and with just 5% energy resolution for JUNO.

  • 110.
    Choubey, Sandhya
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Goswami, Srubabati
    Gupta, Chandan
    Lakshmi, S. M.
    Thakore, Tarak
    Sensitivity to neutrino decay with atmospheric neutrinos at the INO-ICAL detector2018In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 97, no 3, article id 033005Article in journal (Refereed)
    Abstract [en]

    Sensitivity of the magnetized Iron Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO) to invisible decay of the mass eigenstate nu(3) using atmospheric neutrinos is explored. A full three-generation analysis including Earth matter effects is performed in a framework with both decay and oscillations. The wide energy range and baselines offered by atmospheric neutrinos are shown to be excellent for constraining the nu(3) lifetime. We find that with an exposure of 500 kton - yr the ICAL atmospheric experiment could constrain the. 3 lifetime to tau(3)/m(3) > 1.51 x 10(-10) s/eV at the 90% C.L. This is 2 orders of magnitude tighter than the bound from MINOS. The effect of invisible decay on the precision measurement of theta(23) and vertical bar Delta m(32)(2)vertical bar is also studied.

  • 111.
    Collado, Arnau Koemans
    et al.
    Queen Mary Univ London, Sch Phys & Astron, Ctr Res String Theory, Mile End Rd, London E1 4NS, England..
    Di Vecchia, Paolo
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Copenhagen, Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.;Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Russo, Rodolfo
    Queen Mary Univ London, Sch Phys & Astron, Ctr Res String Theory, Mile End Rd, London E1 4NS, England..
    Revisiting the second post-Minkowskian eikonal and the dynamics of binary black holes2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 100, no 6, article id 066028Article in journal (Refereed)
    Abstract [en]

    In this paper we study the two-body gravitational scattering of massive scalars with different masses in general spacetime dimensions. We focus on the Regge limit (eikonal regime) of the resulting scattering amplitudes and discuss how to extract the classical information representing the scattering of two black holes. We derive the leading eikonal and explicitly show the resummation of the first leading energy contribution up to second order in Newton's gravitational constant. We also calculate the subleading eikonal showing that in general spacetime dimensions it receives a nontrivial contribution from the box integral. From the eikonal we extract the two-body classical scattering angle between the two black holes up to the second post-Minkowskian order. Taking various probe-limits of the two-body scattering angles we are able to show agreement between our results and various results in the literature. We highlight that the box integral also has a log-divergent (in energy) contribution at subsubleading order which violates perturbative unitarity in the ultrarelativistic limit. We expect this term to play a role in the calculation of the eikonal at the third post-Minkowskian order.

  • 112.
    Cruz, Juan S.
    et al.
    CP3-Origins, Center for Cosmology and Particle Physics Phenomenology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark, Campusvej 55.
    Hannestad, Steen
    Nordita SU.
    Holm, Emil Brinch
    Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
    Niedermann, Florian
    Nordita SU.
    Sloth, Martin S.
    CP3-Origins, Center for Cosmology and Particle Physics Phenomenology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark, Campusvej 55.
    Tram, Thomas
    Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark.
    Profiling cold new early dark energy2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 2, article id 023518Article in journal (Refereed)
    Abstract [en]

    Recent interest in new early dark energy (NEDE), a cosmological model with a vacuum energy component decaying in a triggered phase transition around recombination, has been sparked by its impact on the Hubble tension. Previous constraints on the model parameters were derived in a Bayesian framework with Markov-chain Monte Carlo (MCMC) methods. In this work, we instead perform a frequentist analysis using the profile likelihood in order to assess the impact of prior volume effects on the constraints. We constrain the maximal fraction of NEDE fNEDE, finding fNEDE=0.076-0.035+0.040 at 68% CL with our baseline dataset and similar constraints using either data from SPT-3G, ACT or full-shape large-scale structure, showing a preference over ΛCDM even in the absence of a SH0ES prior on H0. While this is stronger evidence for NEDE than obtained with the corresponding Bayesian analysis, our constraints broadly match those obtained by fixing the NEDE trigger mass. Including the SH0ES prior on H0, we obtain fNEDE=0.136-0.026+0.024 at 68% CL. Furthermore, we compare NEDE with the early dark energy (EDE) model, finding similar constraints on the maximal energy density fractions and H0 in the two models. At 68% CL in the NEDE model, we find H0=69.56-1.29+1.16 km s-1 Mpc-1 with our baseline and H0=71.62-0.76+0.78 km s-1 Mpc-1 when including the SH0ES measurement of H0, thus corroborating previous conclusions that the NEDE model provides a considerable alleviation of the H0 tension.

  • 113.
    Davison, Richard A.
    et al.
    Univ Cambridge, Dept Appl Math & Theoret Phys, Cambridge CB3 0WA, England..
    Gentle, Simon A.
    Univ Utrecht, Inst Theoret Phys, NL-3508 TD Utrecht, Netherlands.;Leiden Univ, Inst Lorentz Theoret Phys, NL-2333 CA Leiden, Netherlands..
    Goutéraux, Blaise
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Paris Saclay, Ctr Theoret Phys, Ecole Polytech, CNRS UMR 7644, F-91128 Palaiseau, France;Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.
    Impact of irrelevant deformations on thermodynamics and transport in holographic quantum critical states2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 100, no 8, article id 086020Article in journal (Refereed)
    Abstract [en]

    We study thermodynamic and transport observables of quantum critical states that arise in the infrared limit of holographic renormalization group flows. Although these observables are expected to exhibit quantum critical scaling, there are a number of cases in which their frequency and temperature dependences are in apparent contradiction with scaling theories. We study two different classes of examples and show in both cases that the apparent breakdown of scaling is a consequence of the dependence of observables on an irrelevant deformation of the quantum critical state. By assigning scaling dimensions to the near-horizon observables, we formulate improved scaling theories that are completely consistent with all explicit holographic results once the dependence on the dangerously irrelevant coupling is properly accounted for. In addition to governing thermodynamic and transport phenomena in these states, we show that the dangerously irrelevant coupling also controls late-time equilibration, which occurs at a rate parametrically slower than the temperature 1/tau(eq) << T. At very late times, transport is diffusion-dominated, with a diffusivity that can be written simply in terms of tau(eq) and the butterfly velocity, D similar to v(B)(2)tau(eq). We conjecture that in such cases there exists a long-lived, propagating collective mode with velocity v, and in this case the relation D = v(s)(2)tau(eq) holds exactly in the limit tau T-eq >> 1.

  • 114.
    Davoudiasl, Hooman
    et al.
    Brookhaven Natl Lab, Phys Dept, High Energy Theory Grp, Upton, NY 11973 USA..
    Denton, Peter B.
    Brookhaven Natl Lab, Phys Dept, High Energy Theory Grp, Upton, NY 11973 USA..
    McGady, David A.
    Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.;Nordita SU.
    Ultralight fermionic dark matter2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 103, no 5, article id 055014Article in journal (Refereed)
    Abstract [en]

    Conventional lore from Tremaine and Gunn excludes fermionic dark matter lighter than a few hundred eV, based on the Pauli exclusion principle. We highlight a simple way of evading this bound with a large number of species that leads to numerous nontrivial consequences. In this scenario there are many distinct species of fermions with quasidegenerate masses and no couplings to the standard model. Nonetheless, gravitational interactions lead to constraints from measurements at the LHC, of cosmic rays, of supernovae, and of black hole spins and lifetimes. We find that the LHC constrains the number of distinct species, bosons or fermions lighter than similar to 500 GeV, to be N less than or similar to 10(62). This, in particular, implies that roughly degenerate fermionic dark matter must be heavier than similar to 10(-14) eV, which thus relaxes the Tremaine-Gunn bound by similar to 16 orders of magnitude. Slightly weaker constraints applying to masses up to similar to 100 TeV exist from cosmic ray measurements while various constraints on masses less than or similar to 10(-10) eV apply from black hole observations. We consider a variety of phenomenological bounds on the number of species of particles. Finally, we note that there exist theoretical considerations regarding quantum gravity which could impose more severe constraints that may limit the number of physical states to N less than or similar to 10(32).

  • 115.
    De Brito, Gustavo P.
    et al.
    CP3-Origins, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.
    Knorr, Benjamin
    Nordita SU; Nordita, Stockholm University, Hannes Alfvéns väg 12, SE-106 91 Stockholm, Sweden.
    Schiffer, Marc
    Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, Ontario N2L 2Y5, Canada.
    On the weak-gravity bound for a shift-symmetric scalar field2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 2, article id 026004Article in journal (Refereed)
    Abstract [en]

    The weak-gravity bound has been discovered in several asymptotically safe gravity-matter systems. It limits the strength of gravitational fluctuations that are compatible with an ultraviolet-complete matter sector and results from the collision of two partial fixed points of the matter system as a function of the strength of the gravitational interactions. In this paper, we will investigate this mechanism in detail for a shift-symmetric scalar field. First, we will study the fixed point structure of the scalar system without gravity. We find indications that the Gaussian fixed point is the only viable fixed point, suggesting that a weak-gravity bound resulting from the collision of two partial fixed points is a truncation artifact. We will then couple the scalar system to gravity and perform different expansions to track the Gaussian fixed point as gravitational fluctuations become stronger. We also introduce a new notion of the weak-gravity bound that is based on the number of relevant operators.

  • 116.
    De Jonckheere, Tim
    et al.
    Vrije Univ Brussel, Theoret Nat Kunde, Pl Laan 2, B-1050 Brussels, Belgium.;Int Solvay Inst, Pl Laan 2, B-1050 Brussels, Belgium..
    Lindgren, Jonathan
    Nordita SU;Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Entanglement entropy in inhomogeneous quenches in AdS(3)/CFT22018In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 98, no 10, article id 106006Article in journal (Refereed)
    Abstract [en]

    We compute entanglement entropy and differential entropy in inhomogeneous holographic quenches in AdS(3)/CFT2. The quenches are arbitrarily inhomogeneous and modeled by an infalling shell of massless nonrotating matter where the final state is not dual to a static black hole but rather to a black hole with time-dependent stress-energy tensor modes. We study the entanglement entropy of an interval and differential entropy of a family of intervals analytically when the inhomogeneities have a perturbative amplitude and numerically for nonperturbative inhomogeneities. While we are in principle able to study these quantities for any inhomogeneities, we discuss two concrete examples: an oscillatory quench and a bilocal quench. Both cases display saturation towards a steady state but do not fully thermalize. Depending on the location and size of the interval, the entanglement entropy displays a variety of interesting phenomena such as plateau phases, bumps, and discontinuities in its first derivative with respect to time.

  • 117.
    Di Vecchia, Paolo
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Marotta, Raffaele
    Complesso Univ Monte S Angelo, Sez Napoli, Ist Nazl Fis Nucl, Edificio 6,Via Cintia, I-80126 Naples, Italy..
    Mojaza, Matin
    Max Planck Inst Gravitat Phys, Albert Einstein Inst, Muhlenberg 1, DE-14476 Potsdam, Germany..
    Multiloop soft theorem of the dilaton in the bosonic string2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 100, no 4, article id 041902Article in journal (Refereed)
    Abstract [en]

    We show that by fixing the multiloop Green function in the closed bosonic string to be Arakelov's Green function, one obtains factorization of scattering amplitudes with a softly emitted dilaton to the same level as with a graviton to all loop order. This extends our previous analysis at one loop to all loop orders and confirms that some high-energy quantum symmetry in the bosonic string protects the factorization of amplitudes with softly emitted dilatons.

  • 118.
    Eberhardt, Andrew
    et al.
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Phys Dept, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA..
    Banerjee, Arka
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Phys Dept, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA..
    Kopp, Michael
    Nordita SU.
    Abel, Tom
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Phys Dept, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA..
    Investigating the use of field solvers for simulating classical systems2020In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 101, no 4, article id 043011Article in journal (Refereed)
    Abstract [en]

    We explore the use of field solvers as approximations of classical Vlasov-Poisson systems. This correspondence is investigated in both electrostatic and gravitational contexts. We demonstrate the ability of field solvers to be excellent approximations of problems with cold initial condition into the nonlinear regime. We also investigate extensions of the Schrodinger-Poisson system that employ multiple stacked cold streams, and the von Neumann-Poisson equation as methods that can successfully reproduce the classical evolution of warm initial conditions. We then discuss how appropriate simulation parameters need to be chosen to avoid interference terms, aliasing, and wave behavior in the field solver solutions. We present a series of criteria clarifying how parameters need to be chosen in order to effectively approximate classical solutions.

  • 119.
    Eberhardt, Andrew
    et al.
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Dept Phys, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA..
    Kopp, Michael
    Nordita SU.
    Zamora, Alvaro
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Dept Phys, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA..
    Abel, Tom
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Dept Phys, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, Menlo Pk, CA 94025 USA..
    Field moment expansion method for interacting bosonic systems2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 8, article id 083007Article in journal (Refereed)
    Abstract [en]

    We introduce a numerical method and PYTHON package, CHiMES, that simulates quantum systems initially well approximated by mean field theory using a second order extension of the classical field approach. We call this the field moment expansion method. In this way, we can accurately approximate the evolution of first and second field moments beyond where the mean field theory breaks down. This allows us to estimate the quantum break time of a classical approximation without any calculations external to the theory. We investigate the accuracy of the field moment expansion using a number of well studied quantum test problems. Interacting bosonic systems similar to scalar field dark matter are chosen as test problems. We find that successful application of this method depends on two conditions: the quantum system must initially be well described by the classical theory, and the growth of the higher order moments must be hierarchical.

  • 120.
    Eberhardt, Andrew
    et al.
    Kavli Institute for the Physics and Mathematics of the Universe (WPI), UTIAS, The University of Tokyo, Chiba 277-8583, Japan.
    Zamora, Alvaro
    Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, 94025, California, USA; Physics Department, Stanford University, Stanford, California, USA; SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025, USA, 2575 Sand Hill Rd.
    Kopp, Michael
    Nordita SU.
    Abel, Tom
    Kavli Institute for Particle Astrophysics and Cosmology, Menlo Park, 94025, California, USA; Physics Department, Stanford University, Stanford, California, USA; SLAC National Accelerator Laboratory, 2575 Sand Hill Rd, Menlo Park, California 94025, USA, 2575 Sand Hill Rd.
    Classical field approximation of ultralight dark matter: Quantum break times, corrections, and decoherence2024In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 109, no 8, article id 083527Article in journal (Refereed)
    Abstract [en]

    The classical field approximation is widely used to better understand the predictions of ultralight dark matter. Here, we use the truncated Wigner approximation method to test the classical field approximation of ultralight dark matter. This method approximates a quantum state as an ensemble of independently evolving realizations drawn from its Wigner function. The method is highly parallelizable and allows the direct simulation of quantum corrections and decoherence times in systems many times larger than have been previously studied in reference to ultralight dark matter. Our study involves simulation of systems in 1, 2, and 3 spatial dimensions. We simulate three systems, the condensation of a Gaussian random field in three spatial dimensions, a stable collapsed object in three spatial dimensions, and the merging of two stable objects in two spatial dimensions. We study the quantum corrections to the classical field theory in each case. We find that quantum corrections grow exponentially during nonlinear growth with the timescale being approximately equal to the system dynamical time. In stable systems the corrections grow quadratically. We also find that the primary effect of quantum corrections is to reduce the amplitude of fluctuations on the de Broglie scale in the spatial density. Finally, we find that the timescale associated with decoherence due to gravitational coupling to baryonic matter is at least as fast as the quantum corrections due to gravitational interactions. These results are consistent with the predictions of the classical field theory being accurate.

  • 121.
    Eberhardt, Andrew
    et al.
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Phys Dept, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA..
    Zamora, Alvaro
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Phys Dept, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA..
    Kopp, Michael
    NORDITA, Stockholm Univ.
    Abel, Tom
    Kavli Inst Particle Astrophys & Cosmol, Menlo Pk, CA 94025 USA.;Stanford Univ, Phys Dept, Stanford, CA 94305 USA.;SLAC Natl Accelerator Lab, 2575 Sand Hill Rd, Menlo Pk, CA 94025 USA..
    Single classical field description of interacting scalar fields2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 105, no 3, article id 036012Article in journal (Refereed)
    Abstract [en]

    We test the degree to which interacting Bosonic systems can be approximated by a classical field as total occupation number is increased. This is done with our publicly available code repository, QIBS, a new massively parallel solver for these systems. We use a number of toy models well studied in the literature and track when the classical field description admits quantum corrections, called the quantum breaktime. This allows us to test claims in the literature regarding the rate of convergence of these systems to the classical evolution. We test a number of initial conditions, including coherent states, number eigenstates, and field number states. We find that of these initial conditions, only number eigenstates do not converge to the classical evolution as occupation number is increased. We find that systems most similar to scalar field dark matter exhibit a logarithmic enhancement in the quantum breaktime with total occupation number. Systems with contact interactions or with field number state initial conditions, and linear dispersions, exhibit a power law enhancement. Finally, we find that the breaktime scaling depends on both model interactions and initial conditions.

  • 122.
    Edwards, Thomas D. P.
    et al.
    Univ Amsterdam, Inst Theoret Phys Amsterdam, Gravitat Astroparticle Phys Amsterdam GRAPPA, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands.;Univ Amsterdam, Delta Inst Theoret Phys, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands..
    Kavanagh, Bradley J.
    Univ Amsterdam, Inst Theoret Phys Amsterdam, Gravitat Astroparticle Phys Amsterdam GRAPPA, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands.;Univ Amsterdam, Delta Inst Theoret Phys, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands..
    Weniger, Christoph
    Univ Amsterdam, Inst Theoret Phys Amsterdam, Gravitat Astroparticle Phys Amsterdam GRAPPA, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands.;Univ Amsterdam, Delta Inst Theoret Phys, Sci Pk 904, NL-1098 XH Amsterdam, Netherlands..
    Baum, Sebastian
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Dept Phys, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden ; Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden.
    Drukier, Andrzej K.
    Stockholm Univ, Dept Phys, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden..
    Freese, Katherine
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Dept Phys, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden ; Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden ; Univ Michigan, Leinweber Ctr Theoret Phys, Ann Arbor, MI 48109 USA.
    Gorski, Maciej
    Natl Ctr Nucl Res, PL-05400 Otwock, Swierk, Poland..
    Stengel, Patrick
    Stockholm Univ, Dept Phys, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden..
    Digging for dark matter: Spectral analysis and discovery potential of paleo-detectors2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 4, article id 043541Article in journal (Refereed)
    Abstract [en]

    Paleo-detectors are a recently proposed method for the direct detection of dark matter (DM). In such detectors, one would search for the persistent damage features left by DM-nucleus interactions in ancient minerals. Initial sensitivity projections have shown that paleo-detectors could probe much of the remaining weakly interacting massive particle (WIMP) parameter space. In this paper, we improve upon the cut-and-count approach previously used to estimate the sensitivity by performing a full spectral analysis of the background-and DM-induced signal spectra. We consider two scenarios for the systematic errors on the background spectra: (i) systematic errors on the normalization only, and (ii) systematic errors on the shape of the backgrounds. We find that the projected sensitivity is rather robust to imperfect knowledge of the backgrounds. Finally, we study how well the parameters of the true WIMP model could be reconstructed in the hypothetical case of a WIMP discovery.

  • 123.
    Escriva, Albert
    et al.
    Nagoya Univ, Grad Sch Sci, Div Particle & Astrophys Sci, Nagoya 4648602, Japan..
    Subils, Javier G.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA.
    Primordial black hole formation during a strongly coupled crossover2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 107, no 4, article id L041301Article in journal (Refereed)
    Abstract [en]

    The final mass distribution of primordial black holes is sensitive to the equation of state of the Universe at the scales accessible by the power spectrum. Motivated by the presence of phase transitions in several beyond the Standard Model theories, some of which are strongly coupled, we analyze the production of primordial black holes during such phase transitions, which we model using the gauge/gravity duality. We focus in the (often regarded as physically uninteresting) case for which the phase transition is just a smooth crossover. We find an enhancement of primordial black hole production in the range MPBH is an element of [10-16; 10-6]M circle dot.

  • 124.
    Faedo, Anton F.
    et al.
    Univ Oviedo, Dept Fis, C Leopoldo Calvo Sotelo 18, ES-33007 Oviedo, Spain.;Univ Oviedo, Inst Ciencias & Tecnol Espaciales Asturias ICTEA, C Independencia 13, ES-33004 Oviedo, Spain..
    Hoyos, Carlos
    Univ Oviedo, Inst Ciencias & Tecnol Espaciales Asturias ICTEA, C Independencia 13, ES-33004 Oviedo, Spain..
    Subils, Javier G.
    Nordita SU.
    Baryonic matter at strong coupling: Confining superfluids and deconfined ferromagnets2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 8, article id 086028Article in journal (Refereed)
    Abstract [en]

    We study the phase diagram of a strongly coupled confining theory in 2 thorn 1 dimensions, as a function of temperature and baryon chemical potential. The theory has a fully fledged supergravity holographic dual, that we use to predict a line of first-order phase transitions separating a confining phase and a deconfined phase. Both phases exhibit a nonzero baryon density thus providing a first example of baryonic matter in a confining string dual that does not require the introduction of flavor branes. We argue that the confining phase is a baryon superfluid, while the deconfined phase has nonzero baryon magnetization.

  • 125.
    Ferreira, Ricardo Z.
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.;Inst Fis Altes Energies IFAE, Campus UAB, Barcelona 08193, Spain.;Barcelona Inst Sci & Technol BIST, Campus UAB, Barcelona 08193, Spain..
    Notari, Alessio
    Univ Barcelona, Dept Fis Quant & Astrofis, Marti i Franques 1, Barcelona 08028, Spain.;Univ Barcelona, Inst Ciencies Cosmos ICCUB, Marti i Franques 1, Barcelona 08028, Spain..
    Rompineve, Fabrizio
    Tufts Univ, Inst Cosmol, Dept Phys & Astron, Medford, MA 02155 USA..
    Dine-Fischler-Srednicki-Zhitnitsky axion in the CMB2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 103, no 6, article id 063524Article in journal (Refereed)
    Abstract [en]

    We perform for the first time a dedicated analysis of cosmological constraints on Dine-Fischler-Srednicki-Zhitnitsky (DFSZ) QCD axion models. Such constructions are especially interesting in light of the recent XENON rrexcess and of hints from stellar cooling. In DFSZ models, for m(a) greater than or similar to 0.1 eV, scatterings of pions and muons can produce a sizable cosmic background of thermal axions, that behave similarly to massive neutrinos. However, the pion coupling depends on the alignment between the vacuum expectation value (vevs) of two Higgs doublets, and can be significantly suppressed or enhanced with respect to the Kim-Shifman-Vainshtein-Zakharov scenario (KSVZ). Using the latest Planck and BAO data, we find m(a) <= 0.2 eV at 95% C.L., when the axion coupling to pions c(a pi) is maximal. Constraints on m(a), instead, can be significantly relaxed when c(a pi) is small. In particular, we point out that in the so-called DFSZ-II model, where the axion coupling to leptons does not vanish simultaneously with c(a pi), production via muons gives m(a) < 0.6 eV at 95% C.L., whereas in the DFSZ-I model bounds on m a can be fully lifted. We then combine cosmological data with recent hints of a DFSZ axion coupled to electrons from the XENON1T experiment, finding in this case that the axion mass is constrained to be in the window 0.07 eV less than or similar to m(a) less than or similar to 1.8(0.3) eV for the DFSZ-I (DFSZ-II) model. A similar analysis with stellar cooling hints gives 3 meV less than or similar to m(a) less than or similar to 0.2 eV for DFSZ-II, while no constraint arises in the DFSZ-I case. Forthcoming cosmic microwave background stage 4 experiments will be able to further test such scenarios; for instance the XENON1T window should be fully probed at 2 sigma for a DFSZ-I axion.

  • 126.
    Filmer, E. K.
    et al.
    Department of Physics, University of Adelaide, Adelaide, Australia.
    Leopold, Alexander
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lundberg, Olof
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ohm, Christian
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ripellino, Giulia
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Shaheen, Rabia
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Shope, David R.
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Tipton, P.
    Department of Physics, Yale University, New Haven, Connecticut, USA.
    et al.,
    Measurements of Higgs boson production by gluon-gluon fusion and vector-boson fusion using H→WW*→eνμν decays in pp collisions at Formula Presented with the ATLAS detector2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 3, article id 032005Article in journal (Refereed)
    Abstract [en]

    Higgs boson production via gluon-gluon fusion and vector-boson fusion in proton-proton collisions is measured in the H → W W * → e ν μ ν decay channel. The Large Hadron Collider delivered proton-proton collisions at a center-of-mass energy of 13 TeV between 2015 and 2018, which were recorded by the ATLAS detector, corresponding to an integrated luminosity of 139 fb - 1 . The total cross sections for Higgs boson production by gluon-gluon fusion and vector-boson fusion times the H → W W * branching ratio are measured to be 12.0 ± 1.4 and 0.75 - 0.16 + 0.19 pb , respectively, in agreement with the Standard Model predictions of 10.4 ± 0.6 and 0.81 ± 0.02 pb . Higgs boson production is further characterized through measurements of Simplified Template Cross Sections in a total of 11 kinematic fiducial regions.

  • 127.
    Filmer, E. K.
    et al.
    Department of Physics, University of Adelaide, Adelaide, Australia.
    Leopold, Alexander
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lundberg, Olof
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ohm, Christian
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Shaheen, Rabia
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Tipton, P.
    Department of Physics, Yale University, New Haven, Connecticut, USA.
    et al.,
    Measurement of the production of a W boson in association with a charmed hadron in pp collisions at Formula Presented with the ATLAS detector2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 3, article id 032012Article in journal (Refereed)
    Abstract [en]

    The production of a W boson in association with a single charm quark is studied using 140 fb - 1 of s = 13 TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider. The charm quark is tagged by the presence of a charmed hadron reconstructed with a secondary-vertex fit. The W boson is reconstructed from the decay to either an electron or a muon and the missing transverse momentum present in the event. The charmed mesons reconstructed are D + → K - π + π + and D * + → D 0 π + → ( K - π + ) π + and the charge conjugate decays in the fiducial regions where p T ( e , μ ) > 30 GeV , | η ( e , μ ) | < 2.5 , p T ( D ( * ) ) > 8 GeV , and | η ( D ( * ) ) | < 2.2 . The integrated and normalized differential cross sections as a function of the pseudorapidity of the lepton from the W boson decay, and of the transverse momentum of the charmed hadron, are extracted from the data using a profile likelihood fit. The measured total fiducial cross sections are σ fid OS - SS ( W - + D + ) = 50.2 ± 0.2 ( stat ) - 2.3 + 2.4 ( syst ) pb , σ fid OS - SS ( W + + D - ) = 48.5 ± 0.2 ( stat ) - 2.2 + 2.3 ( syst ) pb , σ fid OS - SS ( W - + D * + ) = 51.1 ± 0.4 ( stat ) - 1.8 + 1.9 ( syst ) pb , and σ fid OS - SS ( W + + D * - ) = 50.0 ± 0.4 ( stat ) - 1.8 + 1.9 ( syst ) pb . Results are compared with the predictions of next-to-leading-order quantum chromodynamics calculations performed using state-of-the-art parton distribution functions. Additionally, the ratio of charm to anticharm production cross sections is studied to probe the s - s ¯ quark asymmetry. The ratio is found to be R c ± = 0.971 ± 0.006 ( stat ) ± 0.011 ( syst ) . The ratio and cross-section measurements are consistent with the predictions obtained with parton distribution function sets that have a symmetric s - s ¯ sea, indicating that any s - s ¯ asymmetry in the Bjorken- x region relevant for this measurement is small.

  • 128.
    Filmer, E. K.
    et al.
    Department of Physics, University of Adelaide, Adelaide, Australia.
    Leopold, Alexander
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lundberg, Olof
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ohm, Christian
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Shaheen, Rabia
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Tipton, P.
    Department of Physics, Yale University, New Haven, Connecticut, USA.
    et al.,
    Search for a new pseudoscalar decaying into a pair of muons in events with a top-quark pair at Formula Presented with the ATLAS detector2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 9, article id 092007Article in journal (Refereed)
    Abstract [en]

    A search for a new pseudoscalar Formula Presented-boson produced in events with a top-quark pair, where the Formula Presented-boson decays into a pair of muons, is performed using Formula Presented Formula Presented collision data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of Formula Presented. The search targets the final state where only one top quark decays to an electron or muon, resulting in a signature with three leptons Formula Presented and Formula Presented. No significant excess of events above the Standard Model expectation is observed and upper limits are set on two signal models: Formula Presented and Formula Presented with Formula Presented, Formula Presented, where Formula Presented, in the mass ranges Formula Presented and Formula Presented.

  • 129.
    Franzmann, Guilherme
    et al.
    Nordita SU;Stockholm Univ, Hannes Alfvens vag 12, SE-10691 Stockholm, Sweden.;Basic Res Community Phys eV, Mariannenstr 89, Leipzig, Germany..
    Jovancic, Sebastian
    KTH. Stockholm Univ, Hannes Alfvens vag 12, SE-10691 Stockholm, Sweden..
    Lawson, Matthew
    Savantic AB, Rosenlundsgatan 52, Stockholm, Sweden..
    Relative distance of entangled systems in emergent spacetime scenarios2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 107, no 6, article id 066008Article in journal (Refereed)
    Abstract [en]

    Spacetime emergence from entanglement proposes an alternative to quantizing gravity and typically derives a notion of distance based on the amount of mutual information shared across subsystems. Albeit promising, this program still faces challenges to describe simple physical systems, such as a maximally entangled Bell pair that is taken apart while preserving its entanglement. We propose a solution to this problem: a reminder that quantum systems can have multiple sectors of independent degrees of freedom, and that each sector can be entangled. Thus, while one sector can decohere, and decrease the amount of total mutual information within the system, another sector, e.g. spin, can remain entangled. We illustrate this with a toy model, showing that only within the particles' momentum uncertainty there can be considerably more entanglement than in the spin sector for a single Bell pair. We finish by introducing some considerations about how spacetime could be tested in the lab in the future.

  • 130.
    Freese, Katherine
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Texas Austin, Dept Phys, Austin, TX 78712 USA.;Univ Stockholm, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden..
    Winkler, Martin Wolfgang
    Univ Texas Austin, Dept Phys, Austin, TX 78712 USA.;Univ Stockholm, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden..
    Chain early dark energy: A Proposal for solving the Hubble tension and explaining today's dark energy2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 8, article id 083533Article in journal (Refereed)
    Abstract [en]

    We propose a new model of early dark energy (EDE) as a possible solution to the Hubble tension in cosmology, the apparent discrepancy between local measurements of the Hubble constant H-0 similar or equal to 74 km s(-1) Mpc(-1) and H-0 similar or equal to 67 km s(-1) Mpc(-1) inferred from the cosmic microwave background (CMB). In chain EDE, the universe undergoes a series of first order phase transitions, starting at a high energy vacuum in a potential, and tunneling down through a chain of every lower energy metastable minima. As in all EDE models, the contribution of the vacuum energy to the total energy density of the universe is initially negligible, but reaches similar to 10% around matter-radiation equality, before cosmological data require it to redshift away quickly-at least as fast as radiation. We indeed obtain this required behavior with a series of N tunneling events, and show that for N > 600 the phase transitions are rapid enough to allow fast percolation and thereby avoid large scale anisotropies in the CMB. We construct a specific example of chain EDE featuring a scalar field in a quasiperiodic potential (a tilted cosine), which is ubiquitous in axion physics and, therefore, carries strong theoretical motivation. Interestingly, the energy difference between vacua can be roughly the size of today's dark energy (milli-electron-volt scale). Therefore, the end result of chain EDE could provide a natural explanation of dark energy, if the tunneling becomes extremely slow in the final step before the field reaches zero (or negative) energy. We discuss a simple mechanism which can stop the scalar field in the desired minimum. Thus chain EDE offers the exciting prospect to explain EDE and dark energy by the same scalar field.

  • 131.
    Freese, Katherine
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Texas Austin, Dept Phys, Austin, TX 78712 USA.;Univ Stockholm, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden..
    Winkler, Martin Wolfgang
    Univ Texas Austin, Dept Phys, Austin, TX 78712 USA.;Univ Stockholm, Oskar Klein Ctr Cosmoparticle Phys, S-10691 Stockholm, Sweden..
    Dark matter and gravitational waves from a dark big bang2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 107, no 8, article id 083522Article in journal (Refereed)
    Abstract [en]

    The hot big bang is often considered as the origin of all matter and radiation in the Universe. Primordial nucleosynthesis provides strong evidence that the early Universe contained a hot plasma of photons and baryons with a temperature T > MeV. However, the earliest probes of dark matter originate from much later times around the epoch of structure formation. In this work we describe a scenario in which dark matter (and possibly dark radiation) can be formed around or even after primordial nucleosynthesis in a second big bang, which we dub the "dark big bang." The latter occurs through a phase transition in the dark sector that transforms dark vacuum energy into a hot dark plasma of particles; in this paper we focus on a first-order phase transition for the dark big bang. The correct dark matter abundance can be set by dark matter cannibalism or by pair annihilation within the dark sector followed by a thermal freeze-out. Alternatively ultraheavy "dark-zilla" dark matter can originate directly from bubble collisions during the dark big bang. We will show that the dark big bang is consistent with constraints from structure formation and the cosmic microwave background if it occurred when the Universe was less than one month old, corresponding to a temperature in the visible sector above OokeV thorn . While the dark matter evades direct and indirect detection, the dark big bang gives rise to striking gravity wave signatures to be tested at pulsar timing array experiments. Furthermore, the dark big bang allows for realizations of self-interacting and/or warm dark matter, which suggest exciting discovery potential in future small-scale structure observations.

  • 132.
    Freese, Katherine
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA; Oskar Klein Center for Cosmoparticle Physics, University of Stockholm, 10691 Stockholm, Sweden.
    Winkler, Martin Wolfgang
    Department of Physics, The University of Texas at Austin, Austin, Texas 78712, USA; Oskar Klein Center for Cosmoparticle Physics, University of Stockholm, 10691 Stockholm, Sweden.
    Have pulsar timing arrays detected the hot big bang: Gravitational waves from strong first order phase transitions in the early Universe2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 106, no 10, article id 103523Article in journal (Refereed)
    Abstract [en]

    The origins of matter and radiation in the universe lie in a hot big bang. We present a number of well-motivated cosmologies in which the big bang occurs through a strong first-order phase transition - either at the end of inflation, after a period of kination ("kination-induced big bang"), or after a second period of vacuum domination in the early Universe ("supercooled big bang"); we also propose a "dark big bang"where only the dark matter in the Universe is created in a first-order phase transition much after inflation. In all of these scenarios, the resulting gravitational radiation can explain the tentative signals reported by the NANOGrav, Parkes, and European Pulsar Timing Array experiments if the reheating temperature of the hot big bang, and correspondingly the energy scale of the false vacuum, falls in the range T∗∼ρvac1/4=MeV-100 GeV. All of the same models at higher reheating temperatures will be of interest to upcoming ground- and space-based interferometer searches for gravitational waves at larger frequency.

  • 133.
    Gardner, James W.
    et al.
    Australian Natl Univ, Ctr Gravitat Astrophys, Acton, ACT 2601, Australia. Australian Natl Univ, OzGrav ANU, Australian Res Council Ctr Excellence Gravitat Wa, Acton, ACT 2601, Australia..
    Yap, Min Jet
    Adya, Vaishali
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Chua, Sheon
    Slagmolen, Bram J. J.
    McClelland, David E.
    Nondegenerate internal squeezing: An all-optical, loss-resistant quantum technique for gravitational-wave detection2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 106, no 4, article id L041101Article in journal (Refereed)
    Abstract [en]

    The detection of kilohertz-band gravitational waves promises discoveries in astrophysics, exotic matter, and cosmology. To improve the kilohertz quantum noise-limited sensitivity of interferometric gravitational -wave detectors, we investigate nondegenerate internal squeezing: optical parametric oscillation inside the signal-recycling cavity with distinct signal-mode and idler-mode frequencies. We use an analytic Hamiltonian model to show that this stable, all-optical technique is tolerant to decoherence from optical detection loss and that it, with its optimal readout scheme, is feasible for broadband sensitivity enhancement.

  • 134.
    Geilhufe, Matthias
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden..
    Kahlhoefer, Felix
    Rhein Westfal TH Aachen, Inst Theoret Particle Phys & Cosmol TTK, D-52056 Aachen, Germany..
    Winkler, Martin Wolfgang
    Stockholm Univ, Oskar Klein Ctr Cosmoparticle Phys, Dept Phys, S-10691 Stockholm, Sweden..
    Dirac materials for sub-MeV dark matter detection: New targets and improved formalism2020In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 101, no 5, article id 055005Article in journal (Refereed)
    Abstract [en]

    Because of their tiny band gaps Dirac materials promise to improve the sensitivity for dark matter particles in the sub-MeV mass range by many orders of magnitude. We study several candidate materials and calculate the expected rates for dark matter scattering via light and heavy dark photons as well as for dark photon absorption. A particular emphasis is placed on how to distinguish a dark matter signal from background by searching for the characteristic daily modulation of the signal, which arises from the directional sensitivity of anisotropic materials in combination with the rotation of Earth. We revisit and improve previous calculations and propose two new candidate Dirac materials: bis(naphthoquinone)tetrathiafulvalene (BNQ-TTF) and Yb3PbO. We perform detailed calculations of the band structures of these materials and of ZrTe5 based on density functional theory and determine the band gap, the Fermi velocities, and the dielectric tensor. We show that in both ZrTe5 and BNQ-TTF the amplitude of the daily modulation can be larger than 10% of the total rate, allowing us to probe the preferred regions of parameter space even in the presence of sizable backgrounds. BNQ-TTF is found to be particularly sensitive to small dark matter masses (below 100 keV for scattering and below 50 meV for absorption), while Yb3PbO performs best for heavier particles.

  • 135.
    Giorgini, Ludovico T.
    et al.
    Nordita SU; Stockholm Univ, S-10691 Stockholm, Sweden..
    Jentschura, Ulrich D.
    Missouri Univ Sci & Technol, Dept Phys, Rolla, MO 65409 USA.;MTA Particle Phys Res Grp, POB 51, H-4001 Debrecen, Hungary..
    Malatesta, Enrico M.
    Bocconi Univ, Dept Comp Sci, Via Sarfatti 25, I-20136 Milan, Italy.;Bocconi Univ, Artificial Intelligence Lab, I-20136 Milan, Italy.;Bocconi Univ, Inst Data Sci & Analyt, I-20136 Milan, Italy..
    Parisi, Giorgio
    Sapienza Univ Roma, Dipartimento Fis, Ple Aldo Moro 5, I-00185 Rome, Italy.;Ist Nazl Fis Nucl, Sez Roma, Ple Aldo Moro 5, I-00185 Rome, Italy.;Inst Nanotechnol NANOTEC CNR, Rome Unit, Ple Aldo Moro 5, I-00185 Rome, Italy..
    Rizzo, Tommaso
    Inst Complex Syst ISC CNR, Rome Unit, Ple Aldo Moro 5, I-00185 Rome, Italy.;Sapienza Univ Roma, Dipartimento Fis, Ple Aldo Moro 5, I-00185 Rome, Italy..
    Zinn-Justin, Jean
    Paris Saclay, IRFU CEA, F-91191 Gif Sur Yvette, France..
    Correlation functions of the anharmonic oscillator: Numerical verification of two-loop corrections to the large-order behavior2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 105, no 10, article id 105012Article in journal (Refereed)
    Abstract [en]

    Recently, the large-order behavior of correlation functions of the O(N)-anharmonic oscillator has been analyzed by us [L. T. Giorgini et al., Phys. Rev. D 101, 125001 (2020)]. Two-loop corrections about the instanton configurations were obtained for the partition function, the two-point and four-point functions, and the derivative of the two-point function at zero momentum transfer. Here, we attempt to verify the obtained analytic results against numerical calculations of higher-order coefficients for the O(1), O(2), and O(3) oscillators, and we demonstrate the drastic improvement of the agreement of the large-order asymptotic estimates and perturbation theory upon the inclusion of the two-loop corrections to the large-order behavior.

  • 136.
    Grandi, Nicolas
    et al.
    Consejo Nacl Invest Cient & Tecn, Inst Fis La Plata, CC 67, RA-1900 La Plata, Argentina.;UNLP, Dept Fis, Calle 49 & 115 S-N, RA-1900 La Plata, Argentina..
    Juričić, Vladimir
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Tecn Federico Santa Maria, Dept Fis, Casilla 110, Valparaiso, Chile.;Stockholm Univ, Hannes Alfvens vag 12, S-10691 Stockholm, Sweden..
    Landea, Ignacio Salazar
    Consejo Nacl Invest Cient & Tecn, Inst Fis La Plata, CC 67, RA-1900 La Plata, Argentina..
    Soto-Garrido, Rodrigo
    Pontificia Univ Catolica Chile, Fac Fis, Vicuna Mackenna, Santiago 4860, Chile..
    Engineering holographic flat fermionic bands2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 105, no 8, article id L081902Article in journal (Refereed)
    Abstract [en]

    In electronic systems with flat bands, such as twisted bilayer graphene, interaction effects govern the structure of the phase diagram. In this paper, we show that a strongly interacting system featuring fermionic flat bands can be engineered using the holographic duality. In particular, we find that in the holographic nematic phase, two bulk Dirac cones separated in momentum space at low temperature, approach each other as the temperature increases. They eventually collide at a critical temperature yielding a flattened band with a quadratic dispersion. On the other hand, in the symmetric (Lifshitz) phase, this quadratic dispersion relation holds for any finite temperature. We therefore obtain a first holographic, strong-coupling realization of a topological phase transition where two Berry monopoles of charge one merge into a single one with charge two, which may be relevant for two-and three-dimensional topological semimetals.

  • 137.
    Halcrow, Chris
    et al.
    KTH, School of Engineering Sciences (SCI), Physics.
    Harland, Derek
    School of Mathematics, University of Leeds, Leeds, LS2 9JT, United Kingdom.
    Nucleon-nucleon potential from instanton holonomies2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 106, no 9, article id 094011Article in journal (Refereed)
    Abstract [en]

    We derive the nucleon-nucleon interaction from the Skyrme model using the instanton and product approximations to skyrmion dynamics. In doing so, we also calculate the classical potential and metric for skyrmion dynamics in each of the approximations. This is the first time they have been compared in detail and the results show major disagreements between the approximations. We derive the eight low-energy nucleon-nucleon interaction potentials and compare them with the Paris model. For the instanton approximation we find strong negative isoscalar and isovector spin-orbit potentials, matching phenomenological models and our geometric intuition. Results for the other potentials are mixed, in part due to the zero pion mass limit used in this approximation.

  • 138.
    Hansen, Dennis
    et al.
    Swiss Fed Inst Technol, Inst Theoret Phys, Wolfgang Pauli Str 27, CH-8093 Zurich, Switzerland..
    Hartong, Jelle
    Univ Edinburgh, Sch Math, Peter Guthrie Tait Rd, Edinburgh EH9 3FD, Midlothian, Scotland.;Univ Edinburgh, Maxwell Inst Math Sci, Peter Guthrie Tait Rd, Edinburgh EH9 3FD, Midlothian, Scotland..
    Obers, Niels A.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Copenhagen, Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark..
    Oling, Gerben
    Univ Copenhagen, Niels Bohr Inst, Blegdamsvej 17, DK-2100 Copenhagen O, Denmark..
    Galilean first-order formulation for the nonrelativistic expansion of general relativity2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 6, article id L061501Article in journal (Refereed)
    Abstract [en]

    We reformulate the Palatini action for general relativity in terms of moving frames that exhibit local Galilean covariance in a large speed of light expansion. For this, we express the action in terms of variables that are adapted to a Galilean subgroup of the GL(n, R) structure group of a general frame bundle. This leads to a novel Palatini-type formulation of general relativity that provides a natural starting point for a first-order nonrelativistic expansion. in doing so, we show how a comparison of Lorentzian and Newton-Cartan metric compatibility explains the appearance of torsion in the nonrelativistic expansion.

  • 139.
    Harko, Tiberiu
    et al.
    Babes Bolyai Univ, Dept Phys, Kogalniceanu St, Cluj Napoca 400084, Romania.;Sun Yat Sen Univ, Sch Phys, Guangzhou 510275, Guangdong, Peoples R China.;UCL, Dept Math, Gower St, London W E 6BT, England..
    Koivisto, Tomi S.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, S-10691 Stockholm, Sweden..
    Lobo, Francisco S. N.
    Univ Lisbon, Fac Ciencias, Inst Astrofis & Ciencias Espaco, Edificio C8, P-1749016 Lisbon, Portugal.;Univ Lisbon, Fac Ciencias, Dept Fis, Edificio C8, P-1749016 Lisbon, Portugal..
    Olmo, Gonzalo J.
    Univ Valencia, CSIC, Ctr Mixto Univ Valencia, Dept Fis Teor, E-46100 Valencia, Spain.;Univ Valencia, CSIC, Ctr Mixto Univ Valencia, IFIC, E-46100 Valencia, Spain.;Univ Fed Paraiba, Dept Fis, BR-58051900 Joao Pessoa, Paraiba, Brazil..
    Rubiera-Garcia, Diego
    Univ Lisbon, Fac Ciencias, Inst Astrofis & Ciencias Espaco, Edificio C8, P-1749016 Lisbon, Portugal..
    Coupling matter in modified Q gravity2018In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 98, no 8, article id 084043Article in journal (Refereed)
    Abstract [en]

    We present a novel theory of gravity by considering an extension of symmetric teleparallel gravity. This is done by introducing, in the framework of the metric-affine formalism, a new class of theories where the nonmetricity Q is nonminimally coupled to the matter Lagrangian. More specifically, we consider a Lagrangian of the form L similar to f(1)(Q) + f(2)(Q)L-M, where f(1) and f(2) are generic functions of Q, and L-M is the matter Lagrangian. This nonminimal coupling entails the nonconservation of the energy-momentum tensor, and consequently the appearance of an extra force. The formulation of the gravity sector in terms of the Q instead of the curvature may result in subtle improvements of the theory. In the context of nonminimal matter couplings, we are therefore motivated to explore whether the new geometrical formulation in terms of the Q, when implemented also in the matter sector, would allow more universally consistent and viable realizations of the nonminimal coupling. Furthermore, we consider several cosmological applications by presenting the evolution equations and imposing specific functional forms of the functions f(1)(Q) and f(2)(Q), such as power-law and exponential dependencies of the nonminimal couplings. Cosmological solutions are considered in two general classes of models, and found to feature accelerating expansion at late times.

  • 140.
    Heissenberg, Carlo
    Stockholm University, Hannes Alfvéns väg 12, SE-11419 Stockholm, Sweden; School of Mathematical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, United Kingdom.
    Angular momentum loss due to spin-orbit effects in the post-Minkowskian expansion2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 10, article id 106003Article in journal (Refereed)
    Abstract [en]

    We calculate the spin-orbit corrections to the loss of angular momentum in a two-body scattering at third post-Minkowskian order, O(G3), from scattering amplitudes using the eikonal operator. These results include effects linear in spin, are valid for generic spin orientations, and are presented in a manifestly Poincaré covariant way. We include both radiative losses, by means of the leading-order gravitational waveform, and static losses, by means of the appropriate -i0 prescription in the leading soft graviton theorem, finding agreement with known results in the post-Newtonian limit.

  • 141.
    Heissenberg, Carlo
    NORDITA SU; Uppsala Univ, Dept Phys & Astron, Box 516, S-75120 Uppsala, Sweden..
    Infrared divergences and the eikonal exponentiation2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 4, article id 046016Article in journal (Refereed)
    Abstract [en]

    The aim of this article is to explore the interplay between the eikonal resummation in impact-parameter space and the exponentiation of infrared divergences in momentum space for gravity amplitudes describing collisions of massive objects. The eikonal governs the classical dynamics relevant to the two-body problem, and its infrared properties are directly linked to the zero-frequency limit of the gravitational wave emission spectrum and to radiation-reaction effects. Combining eikonal and infrared exponentiations it is possible to derive these properties at a given loop order starting from lower-loop data. This is illustrated explicitly in N = 8 supergravity and in general relativity by deriving the divergent part of the two-loop eikonal from tree-level and one-loop elastic amplitudes.

  • 142.
    Hofmann, Stefan
    et al.
    Arnold Sommerfeld Ctr Theoret Phys, Theresien Str 37, D-80333 Munich, Germany..
    Koegler, Maximilian
    Arnold Sommerfeld Ctr Theoret Phys, Theresien Str 37, D-80333 Munich, Germany..
    Niedermann, Florian
    Nordita SU.
    Perturbative quantum consistency near black-hole horizon formation2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 12, article id 125007Article in journal (Refereed)
    Abstract [en]

    We study the prelude to black-hole formation using a suspended shell composed of physical matter that fulfills the dominant energy condition. Here, the collapse of the shell is brought to rest when the formation of the horizon is imminent but has not yet occurred. As the main achievement of this work, we obtain the Feynman propagator which connects the interior and the exterior of the shell within two local coordinate patches. It is derived by drawing an analogy to the propagation of light across interfaces that separate regions with different susceptibilities inside a medium. As a first application, we use this propagator to determine the vacuum persistence amplitude in the presence of external sources. On timescales much shorter than the Page time, we find that the amplitude builds up with time yet remains consistent with perturbative unitarity.

  • 143.
    Hossenfelder, Sabine
    et al.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Frankfurt Inst Adv Studies, Ruth Moufang Str 1, D-60438 Frankfurt, Germany.;Stockholm Univ, NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Zingg, Tobias
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Helsinki, Dept Phys, POB 64, FIN-00014 Helsinki, Finland.;Univ Helsinki, Helsinki Inst Phys, POB 64, FIN-00014 Helsinki, Finland.;Stockholm Univ, NORDITA, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Analog models for holographic transport2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 100, no 5, article id 056015Article in journal (Refereed)
    Abstract [en]

    The gauge-gravity duality and analog gravity both relate a condensed matter system to a gravitational theory. This makes it possible to use gravity as an intermediary to establish a relation between two different condensed matter systems: the strongly coupled system from the gauge-gravity duality and the weakly coupled gravitational analog. We here offer some examples for relations between observables in the two different condensed matter systems. In particular, we show how the equations characterizing Green functions and fast order transport coefficients in holographic models can be mapped to those describing phenomena in an analog gravitational system, which allows, in principle, to obtain the former by measuring the latter.

  • 144.
    Hoyos, Carlos
    et al.
    Univ Oviedo, Dept Phys, C Federico Garcia Lorca 18, ES-33007 Oviedo, Spain.;Inst Ciencias & Tecnol Espaciales Asturias ICTEA, C Federico Garcia Lorca 18, ES-33007 Oviedo, Spain..
    Jokela, Niko
    Univ Helsinki, Dept Phys, POB 64, FI-00014 Helsinki, Finland.;Univ Helsinki, Helsinki Inst Phys, POB 64, FI-00014 Helsinki, Finland..
    Jarvinen, Matti
    Asia Pacif Ctr Theoret Phys, Pohang 37673, South Korea.;Pohang Univ Sci & Technol, Dept Phys, Pohang 37673, South Korea..
    Subils, Javier G.
    KTH, Centres, Nordic Institute for Theoretical Physics NORDITA. Univ Barcelona, Dept Fis Quant & Astrofis, Marti Franques 1, ES-08028 Barcelona, Spain.;Univ Barcelona, Inst Ciencies Cosmos ICC, Marti Franques 1, ES-08028 Barcelona, Spain.;Stockholm Univ, Hannes Alfvens Vag 12, SE-10691 Stockholm, Sweden..
    Tarrio, Javier
    Univ Helsinki, Dept Phys, POB 64, FI-00014 Helsinki, Finland.;Univ Helsinki, Helsinki Inst Phys, POB 64, FI-00014 Helsinki, Finland..
    Vuorinen, Aleksi
    Univ Helsinki, Dept Phys, POB 64, FI-00014 Helsinki, Finland.;Univ Helsinki, Helsinki Inst Phys, POB 64, FI-00014 Helsinki, Finland..
    Holographic approach to transport in dense QCD matter2022In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 105, no 6, article id 066014Article in journal (Refereed)
    Abstract [en]

    The transport properties of dense QCD matter play a crucial role in the physics of neutron stars and their mergers but are notoriously difficult to study with traditional quantum field theory tools. Specializing to the case of unpaired quark matter in beta equilibrium, we approach the problem through the machinery of holography, in particular the V-QCD and D3-D7 models, and derive results for the electrical and thermal conductivities and the shear and bulk viscosities. In addition we compare the bulk to shear viscosity ratio to the speed of sound and find that it violates the so-called Buchel bound. Our results differ dramatically from earlier predictions of perturbative QCD, the root causes and implications of which we analyze in detail.

  • 145.
    Huang, Guo-yuan
    et al.
    Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China.;Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100049, Peoples R China..
    Ohlsson, Tommy
    KTH, School of Engineering Sciences (SCI), Physics, Theoretical Particle Physics. Univ Iceland, Sci Inst, Dunhaga 3, IS-107 Reykjavik, Iceland..
    Zhou, Shun
    Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China.;Univ Chinese Acad Sci, Sch Phys Sci, Beijing 100049, Peoples R China.;Peking Univ, Ctr High Energy Phys, Beijing 100871, Peoples R China..
    Observational constraints on secret neutrino interactions from big bang nucleosynthesis2018In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 97, no 7, article id 075009Article in journal (Refereed)
    Abstract [en]

    We investigate possible interactions between neutrinos and massive scalar bosons via g(phi)(nu) over bar nu phi (or massive vector bosons via g(V)(nu) over bar gamma(mu)nu V-mu) and explore the allowed parameter space of the coupling constant g phi (or g(V)) and the scalar (or vector) boson mass m(phi) (or m(V)) by requiring that these secret neutrino interactions (SNIs) should not spoil the success of big bang nucleosynthesis (BBN). Incorporating the SNIs into the evolution of the early Universe in the BBN era, we numerically solve the Boltzmann equations and compare the predictions for the abundances of light elements with observations. It turns out that the constraint on g(phi) and m(phi) in the scalar-boson case is rather weak, due to a small number of degrees of freedom (d.o.f.). However, in the vector-boson case, the most stringent bound on the coupling g(V) less than or similar to 6 x 10(-10) at 95% confidence level is obtained for m(V) similar or equal to 1 MeV, while the bound becomes much weaker g(V) less than or similar to 8 x 10(-6) for smaller masses m(V) less than or similar to 10(-4) MeV. Moreover, we discuss in some detail how the SNIs affect the cosmological evolution and the abundances of the lightest elements.

  • 146.
    Ilic, Stephane
    et al.
    Czech Acad Sci, Inst Phys, CEICO, Na Slovance 2, Prague 8, Czech Republic.;Sorbonne Univ, Univ PSL, Observ Paris, CNRS,LERMA, F-75014 Paris, France.;Univ Toulouse, UPS, CNES, CNRS,IRAP, Toulouse, France..
    Kopp, Michael
    Nordita SU.
    Skordis, Constantinos
    Czech Acad Sci, Inst Phys, CEICO, Na Slovance 2, Prague 8, Czech Republic..
    Thomas, Daniel B.
    Univ Manchester, Jodrell Bank Ctr Astrophys, Sch Phys & Astron, Manchester M13 9PL, Lancs, England..
    Dark matter properties through cosmic history2021In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 104, no 4, article id 043520Article in journal (Refereed)
    Abstract [en]

    We perform the first test of dark matter (DM) stress-energy evolution through cosmic history, using cosmic microwave background measurements supplemented with baryon acoustic oscillation data and the Hubble Space Telescope key project data. We constrain the DM equation of state (EoS) in 8 redshift bins, and its sound speed and (shear) viscosity in 9 redshift bins, finding no convincing evidence for non-ACDM values in any of the redshift bins. Despite this enlarged parameter space, the sound speed and viscosity are constrained relatively well at late times (due to the inclusion of CMB lensing), whereas the EoS is most strongly constrained around recombination. These results constrain for the first time the level of "coldness" required of DM across various cosmological epochs at both the background and perturbative levels. We show that simultaneously allowing time dependence for both the EoS and sound speed parameters shifts the posterior of the DM abundance before recombination to a higher value, while keeping the present day DM abundance similar to the ACDM value. This shifts the posterior for the present day Hubble constant compared to ACDM, suggesting that DM with time-dependent parameters is well-suited to explore possible solutions to persistent tensions within the ACDM model. We perform a detailed comparison with our previous study involving a vanishing sound speed and viscosity using the same datasets in order to explain the physical mechanism behind these shifts.

  • 147.
    Jackson, P.
    et al.
    Department of Physics, University of Adelaide, Adelaide, Australia.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ohm, Christian
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ripellino, Giulia
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Shope, David R.
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. Department of Physics, Royal Institute of Technology, Stockholm, Sweden.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics. Department of Physics, Royal Institute of Technology, Stockholm, Sweden.
    Tipton, P.
    Department of Physics, Yale University, New Haven, Connecticut, USA.
    et al.,
    Measurement of cross sections for production of a Z boson in association with a flavor-inclusive or doubly b-tagged large-radius jet in proton-proton collisions at Formula Presented with the ATLAS experiment2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 1, article id 012022Article in journal (Refereed)
    Abstract [en]

    We present measurements of cross sections for production of a leptonically decaying Z boson in association with a large-radius jet in 13 TeV proton-proton collisions at the LHC, using 36 fb - 1 of data from the ATLAS detector. Integrated and differential cross sections are measured at particle level in both a flavor inclusive and a doubly b -tagged fiducial phase space. The large-radius jet mass and transverse momentum, its kinematic relationship to the Z boson, and the angular separation of b -tagged small-radius track jets within the large-radius jet are measured. This measurement constitutes an important test of perturbative quantum chromodynamics in kinematic and flavor configurations relevant to several Higgs boson and beyond-Standard-Model physics analyses. The results highlight issues with modeling of additional hadronic activity in the flavor-inclusive selection, and a distinction between flavor-number schemes in the b -tagged phase space.

  • 148.
    Jackson, P.
    et al.
    Department of Physics, University of Adelaide, Adelaide, Australia.
    Lund-Jensen, Bengt
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ohm, Christian
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Ripellino, Giulia
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Sidebo, P. Edvin
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Strandberg, Jonas
    KTH, School of Engineering Sciences (SCI), Physics, Particle and Astroparticle Physics.
    Mkrtchyan, T.
    Yerevan Physics Institute, Yerevan, Armenia.
    et al.,
    Measurement of the inclusive Formula Presented production cross section in the lepton+jets channel in pp collisions at Formula Presented with the ATLAS detector using support vector machines2023In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 108, no 3, article id 032014Article in journal (Refereed)
    Abstract [en]

    A measurement of the top quark pair-production cross section in the lepton + jets decay channel is presented. It is based on 4.6 fb - 1 of s = 7 TeV p p collision data collected during 2011 by the ATLAS experiment at the CERN Large Hadron Collider. A three-class, multidimensional event classifier based on support vector machines is used to differentiate t t ¯ events from backgrounds. The t t ¯ production cross section is found to be σ t t ¯ = 168.5 ± 0.7 ( stat ) - 5.9 + 6.2 ( syst ) - 3.2 + 3.4 ( lumi ) pb . The result is consistent with the Standard Model prediction based on QCD calculations at next-to-next-to-leading order.

  • 149.
    Jalali, Atabak Fathe
    et al.
    KTH, School of Engineering Sciences (SCI), Physics. KTH Royal Inst Technol, Stockholm, Sweden.;Kyoto Univ, Yukawa Inst Theoret Phys YITP, Ctr Gravitat Phys & Quantum Informat CGPQI, Kyoto 6068502, Japan..
    Martens, Paul
    Kyoto Univ, Yukawa Inst Theoret Phys YITP, Ctr Gravitat Phys & Quantum Informat CGPQI, Kyoto 6068502, Japan..
    Mukohyama, Shinji
    Kyoto Univ, Yukawa Inst Theoret Phys YITP, Ctr Gravitat Phys & Quantum Informat CGPQI, Kyoto 6068502, Japan.;Univ Tokyo, Kavli Inst Phys & Math Universe WPI, Kashiwa, Chiba 2778583, Japan..
    Spherical scalar collapse in a type-II minimally modified gravity2024In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 109, no 4, article id 044053Article in journal (Refereed)
    Abstract [en]

    We investigate the spherically symmetric gravitational collapse of a massless scalar field in the framework of a type-II minimally modified gravity theory called VCDM (where V replaces Lambda in the Lambda CDM abbreviation). This theory propagates only two local physical degrees of freedom (DoF) supplemented by the so-called instantaneous (or shadowy) mode. Imposing asymptotically flat spacetime in the standard Minkowski time slicing, one can integrate out the instantaneous mode. Consequently, the equations of motion reduce to those in general relativity (GR) with the maximal slicing. Unlike GR, however, VCDM lacks 4D diffeomorphism invariance, and thus one cannot change the time slicing that is preferred by the theory. We then numerically evolve the system to see if and how a black hole forms. For small amplitudes of the initial scalar profile, we find that its collapse does not generate any black hole, singularity or breakdown of the time slicing. For sufficiently large amplitudes, however, the collapse does indeed result in the formation of an apparent horizon in a finite time. After that, the solution outside the horizon is described by a static configuration, i.e., the Schwarzschild geometry with a finite and timeindependent lapse function. Inside the horizon, on the other hand, the numerical results indicate that the lapse function keeps decreasing toward zero so that the central singularity is never reached. This implies the necessity for a UV completion of the theory to describe physics inside the horizon. Still, we can conclude that VCDM is able to fully describe the entire time evolution of the Universe outside the black hole horizon without knowledge about such a UV completion.

  • 150. K. N., Vishnudath
    et al.
    Choubey, Sandhya
    Goswami, Srubabati
    New sensitivity goal for neutrinoless double beta decay experiments2019In: Physical Review D: covering particles, fields, gravitation, and cosmology, ISSN 2470-0010, E-ISSN 2470-0029, Vol. 99, no 9, article id 095038Article in journal (Refereed)
1234 101 - 150 of 189
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf