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  • 351.
    Månsson, Teresia
    et al.
    Albert Einstein Inst, Max Planck Inst Gravitat Phys.
    Zoubos, Konstantinos
    Univ Copenhagen, Niels Bohr Inst.
    Quantum symmetries and marginal deformations2010Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 10, s. 043-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the symmetries of the N = 1 exactly marginal deformations of N = 4 Super Yang-Mills theory. For generic values of the parameters, these deformations are known to break the SU(3) part of the R-symmetry group down to a discrete subgroup. However, a closer look from the perspective of quantum groups reveals that the Lagrangian is in fact invariant under a certain Hopf algebra which is a non-standard quantum deformation of the algebra of functions on SU(3). Our discussion is motivated by the desire to better understand why these theories have significant differences from N = 4 SYM regarding the planar integrability (or rather lack thereof) of the spin chains encoding their spectrum. However, our construction works at the level of the classical Lagrangian, without relying on the language of spin chains. Our approach might eventually provide a better understanding of the finiteness properties of these theories as well as help in the construction of their AdS/CFT duals.

  • 352.
    Ohlsson, Tommy
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Partikel- och astropartikelfysik. AlbaNova Univ Ctr, Oskar Klein Ctr Cosmoparticle Phys, Roslagstullsbacken 21, SE-10691 Stockholm, Sweden.;Univ Iceland, Sci Inst, Dunhaga 3, IS-107 Reykjavik, Iceland..
    Pernow, Marcus
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Teoretisk partikelfysik. AlbaNova Univ Ctr, Oskar Klein Ctr Cosmoparticle Phys, Roslagstullsbacken 21, SE-10691 Stockholm, Sweden..
    Fits to non-supersymmetric SO(10) models with type I and II seesaw mechanisms using renormalization group evolution2019Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 6, artikel-id 085Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We consider numerical fits to non-supersymmetric SO(10)-based models in which neutrino mass is generated by the type-I or type-II seesaw mechanism or a combination of both. The fits are performed with a sophisticated top-down procedure, taking into account the renormalization group equations of the gauge and Yukawa couplings, integrating out relevant degrees of freedom at their corresponding mass scales, and using recent data for the Standard Model observables. We find acceptable fits for normal neutrino mass ordering only and with neutrino mass generated by either type-I seesaw only or a combination of types I and II seesaw in which type-I seesaw is dominant. Furthermore, we find predictions from the best fit regarding the small neutrino masses, the effective neutrinoless double beta decay mass, and the leptonic CP-violating phase. Finally, we show that the fits are rather insensitive to the chosen value of the unification scale.

  • 353.
    Ohlsson, Tommy
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Teoretisk partikelfysik. AlbaNova Univ Ctr, Oskar Klein Ctr Cosmoparticle Phys, Roslagstullsbacken 21, SE-10691 Stockholm, Sweden.;Univ Iceland, Inst Sci, Dunhaga 3, IS-107 Reykjavik, Iceland..
    Pernow, Marcus
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Teoretisk partikelfysik. AlbaNova Univ Ctr, Oskar Klein Ctr Cosmoparticle Phys, Roslagstullsbacken 21, SE-10691 Stockholm, Sweden..
    Running of fermion observables in non-supersymmetric SO(10) models2018Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 11, artikel-id 028Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We investigate the complete renormalization group running of fermion observables in two different realistic non-supersymmetric models based on the gauge group SO(10) with intermediate symmetry breaking for both normal and inverted neutrino mass orderings. Contrary to results of previous works, we find that the model with the more minimal Yukawa sector of the Lagrangian fails to reproduce the measured values of observables at the electroweak scale, whereas the model with the more extended Yukawa sector can do so if the neutrino masses have normal ordering. The difficulty in finding acceptable fits to measured data is a result of the added complexity from the effect of an intermediate symmetry breaking as well as tension in the value of the leptonic mixing angle theta 23

  • 354.
    Olsson Sax, Olof
    et al.
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Stefański, B., Jr.
    Closed strings and moduli in AdS3/CFT22018Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, Vol. 2018, nr 5, artikel-id 101Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    String theory on AdS3 × S3 × T4 has 20 moduli. We investigate how the perturbative closed string spectrum changes as we move around this moduli space in both the RR and NSNS flux backgrounds. We find that, at weak string coupling, only four of the moduli affect the energies. In the RR background the only effect of these moduli is to change the radius of curvature of the background. On the other hand, in the NSNS background, the moduli introduce worldsheet interactions which enable the use of integrability methods to solve the spectral problem. Our results show that the worldsheet theory is integrable across the 20 dimensional moduli space.

  • 355.
    Ouyang, Hao
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden..
    Holographic four-point functions in Toda field theories in AdS(2)2019Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 4, artikel-id 159Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We consider Toda field theories in a classical Euclidean AdS(2) background. We compute the four-point functions of boundary operators in the a(1), a(2) and b(2) Toda field theories. They take the same form as the four-point functions of generators in the corresponding W-algebras. Therefore we conjecture that the boundary operators are in one-to-one correspondence with the generators in the W-algebras.

  • 356. Puletti, Valentina Giangreco M.
    et al.
    Månsson, Teresia
    KTH, Skolan för teknikvetenskap (SCI), Teoretisk fysik, Matematisk fysik.
    The dual string sigma-model of the SUq(3) sector2012Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, Vol. 2012, nr 1, s. 1-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In four-dimensional N = 4 super Yang-Mills (SYM) the SU(3) sub-sector spanned by purely holomorphic fields is isomorphic to the corresponding mixed one spanned by both holomorphic and anti-holomorphic fields. This is no longer the case when one considers the marginally deformed N = 4 SYM. The mixed SU(3) sector marginally deformed by a complex parameter beta, i.e. SUq(3) with q = e(2i pi beta), has been shown to be integrable at one-loop [1], while it is not the case for the corresponding purely holomorphic one. Moreover, the marginally deformed N = 4 SYM also has a gravity dual constructed by Lunin and Maldacena in [2]. However, the mixed SUq(3) sector has not been studied from the supergravity point of view. Hence in this note, for the case of purely imaginary marginal beta-deformations, we compute the superstring SUq (3) sigma-model in the fast spinning string limit and show that, for rational spinning strings, it reproduces the energy computed via Bethe equations.

  • 357. Roy, B.
    et al.
    Juričić, Vladimir
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Utrecht University, Netherlands .
    Herbut, I. F.
    Emergent Lorentz symmetry near fermionic quantum critical points in two and three dimensions2016Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, Vol. 2016, nr 4, artikel-id 018Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the renormalization group flow of the velocities in the field theory describing the coupling of the massless quasi-relativistic fermions to the bosons through the Yukawa coupling, as well as with both bosons and fermions coupled to a fluctuating U(1) gauge field in two and three spatial dimensions. Different versions of this theory describe quantum critical behavior of interacting Dirac fermions in various condensed-matter systems. We perform an analysis using one-loop ϵ-expansion about three spatial dimensions, which is the upper critical dimension in the problem. In two dimensions, we find that velocities of both charged fermions and bosons ultimately flow to the velocity of light, independently of the initial conditions, the number of fermionic and bosonic flavors, and the value of the couplings at the critical point. In three dimensions, due to the analyticity of the gauge field propagator, both the U(1) charge and the velocity of light flow, which leads to a richer behavior than in two dimensions. We show that all three velocities ultimately flow to a common terminal velocity, which is non-universal and different from the original velocity of light. Therefore, emergence of the Lorentz symmetry in the ultimate infrared regime seems to be a rather universal feature of this class of theories in both two and three dimensions.

  • 358. Russo, J. G.
    et al.
    Zarembo, Konstantin
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Massive N=2 gauge theories at large N2013Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 11, s. 130-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Using exact results obtained from localization on S 4, we explore the large N limit of N = 2 super Yang-Mills theories with massive matter multiplets. We focus on three cases: N = 2* theory, describing a massive hypermultiplet in the adjoint representation, SU(N) super-Yang-Mills with 2 N massive hypermultiplets in the fundamental, and super QCD with massive quarks. When the radius of the four-sphere is sent to infinity the theories at hand are described by solvable matrix models, which exhibit a number of interesting phenomena including quantum phase transitions at finite 't Hooft coupling.

  • 359.
    Russo, Jorge G.
    et al.
    ICREA, Pg Lluis Co 23, Barcelona 08010, Spain.;Univ Barcelona, Dept Fis Cuant & Astrofis, Marti Franques 1, E-08028 Barcelona, Spain.;Univ Barcelona, ICCUB, Marti Franques 1, E-08028 Barcelona, Spain..
    Widen, Erik
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Zarembo, Konstantin
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    N=2 phase transitions and holography2019Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 2, artikel-id 196Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We clarify the relationship between probe analysis of the supergravity al and the large-N solution of the localization matrix model for the anar N=2 super-Yang-Mills theory. A formalism inspired by supergravity lows us to systematically solve the matrix model at strong coupling. ite surprisingly, we find that quantum phase transitions, known to cur in the N=2 theory, start to be visible at the third order of the rong-coupling expansion and thus constitute a perturbative phenomenon the string worldsheet.

  • 360. Russo, Jorge G.
    et al.
    Zarembo, Konstantin
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Evidence for large-N phase transitions in N=2*theory2013Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 4, s. 065-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We solve, using localization, for the large-N master field of N = 2* super-Yang-Mills theory. From that we calculate expectation values of large Wilson loops and the free energy on the four-sphere. At weak coupling, these observables only receive non-perturbative contributions. The analytic solution holds for a finite range of the 't Hooft coupling and terminates at the point of a large-N phase transition. We find evidence that as the coupling is further increased the theory undergoes an infinite sequence of similar transitions that accumulate at infinity.

  • 361.
    Schomerus, Volker
    et al.
    DESY Hamburg, Theory Grp, Notkestr 85, D-22607 Hamburg, Germany..
    Sobko, Evgeny
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    From spinning conformal blocks to matrix Calogero-Sutherland models2018Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 4, artikel-id 052Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper we develop further the relation between conformal four-point blocks involving external spinning fields and Calogero-Sutherland quantum mechanics with matrix-valued potentials. To this end, the analysis of [1] is extended to arbitrary dimensions and to the case of boundary two-point functions. In particular, we construct the potential for any set of external tensor fields. Some of the resulting Schrodinger equations are mapped explicitly to the known Casimir equations for 4-dimensional seed conformal blocks. Our approach furnishes solutions of Casimir equations for external fields of arbitrary spin and dimension in terms of functions on the conformal group. This allows us to reinterpret standard operations on conformal blocks in terms of group-theoretic objects. In particular, we shall discuss the relation between the construction of spinning blocks in any dimension through differential operators acting on seed blocks and the action of left/right invariant vector fields on the conformal group.

  • 362.
    Tiwari, Deepak
    et al.
    Harish Chandra Res Inst HBNI, Chhatnag Rd, Allahabad 211019, Uttar Pradesh, India..
    Choubey, Sandhya
    KTH, Skolan för teknikvetenskap (SCI), Fysik. KTH, Skolan för bioteknologi (BIO), Centra, Albanova VinnExcellence Center for Protein Technology, ProNova. Harish Chandra Res Inst HBNI, Chhatnag Rd, Allahabad 211019, Uttar Pradesh, India..
    Ghosh, Anushree
    Univ Tecn Federico Santa Maria, Dept Fis, Casilla 110-V,Avda Espana 1680, Valparaiso, Chile..
    Prospects of indirect searches for dark matter annihilations in the earth with ICAL@INO2019Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 5, artikel-id 039Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We study the prospects of detecting muon events at the upcoming Iron CALorimeter (ICAL) detector to be built at the proposed India-based Neutrino Observatory (INO) facility due to neutrinos arising out of annihilation of Weakly Interactive Massive Particles (WIMP) in the centre of the earth. The atmospheric neutrinos coming from the direction of earth core presents an irreducible background. We consider 50kt x 10 years of ICAL running and WIMP masses between 10-100 GeV and present 90% C.L. exclusion sensitivity limits on sigma(SI) which is the WIMP-nucleon Spin Independent (SI) interaction cross-section. The expected sensitivity limits calculated for ICAL for the WIMP annihilation in the earth are more stringent than the limits obtained by any other neutrino detector. For a WIMP mass of 52.14 GeV, where the signal fluxes are enhanced due to resonance capture of WIMP in earth due to Fe nuclei, the sensitivity limits, assuming 100% branching ratio for each channel, are: sigma(SI) = 3.43 x 10(-45) cm(2) for channel, sigma(SI) = 1.02 x 10(-44) cm(2) for (+-) channel and sigma(SI) = 5.36 x 10(-44) cm(2) for bb channel.

  • 363.
    Widén, Erik
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Stockholm Univ, Roslagstullsbacken 23, SE-10691 Stockholm, Sweden.;Uppsala Univ, Dept Phys & Astron, SE-75108 Uppsala, Sweden..
    One-point functions in beta-deformed N=4 SYM with defect2018Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 11, artikel-id 114Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We generalize earlier results on one-point functions in N = 4 SYM with a codimension one defect, dual to the D3-D5-brane setup in type IIB string theory on AdS(5)xS(5), to a similar setup in the beta-deformed version of the theory. The treelevel vacuum expectation values of single-trace operators in the two-scalar-subsector are expressed as overlaps between a matrix product state (MPS) and Bethe states in the corresponding twisted spin-chain picture. We comment on the properties of this MPS and present the simplest analytical overlaps and their behavior in a certain limit (of large k). Importantly, we note that the deformation alters earlier interpretations of the MPS as an integrable boundary state, seemingly obstructing simpli fi cations of the overlaps analogous to the compact determinant formula found in the non-deformed theory. The results are supplemented with some supporting numerical results for operators of length eight with four excitations.

  • 364.
    Young, Donovan
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Form factors of chiral primary operators at two loops in ABJ(M)2013Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 6, s. 049-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We calculate the colour-ordered form factor for chiral primary operators built from J scalar fields of ABJ(M) theory to J scalar final states. We work in the 't Hooft limit and show that the leading quantum correction is O(lambda(2)), where lambda is the 't Hooft coupling. We evaluate this leading correction using standard Feynman diagrams and dimensional regularization, and find that the leading divergence is 1/epsilon(2) where the spacetime dimension is d = 3 - 2 epsilon. We further find that the result respects maximal transcendentality.

  • 365. Young, Donovan
    et al.
    Zarembo, Konstantin
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Stockholm University, Stockholm, Sweden; Uppsala University, Uppsala, Sweden; ITEP, Moscow, Russian Federation .
    Holographic dual of the Eguchi-Kawai mechanism2014Ingår i: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, nr 6, s. 030-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The holographic dual of N = 2*, D = 4 supersymmetric Yang-Mills theory has many features common to 5d CFT. We interpret this as a manifestation of Eguchi-Kawai mechanism.

5678 351 - 365 av 365
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