Ändra sökning
Avgränsa sökresultatet
1 - 3 av 3
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Akrami, Yashar
    et al.
    Leiden Univ, Lorentz Inst Theoret Phys, POB 9506, NL-2300 RA Leiden, Netherlands..
    Kuhnel, Florian
    Stockholm Univ, AlbaNova, Oskar Klein Ctr Cosmoparticle Phys, Dept Phys, SE-10691 Stockholm, Sweden..
    Sandstad, Marit
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Uncertainties in primordial black-hole constraints on the primordial power spectrum2018Ingår i: Physics of the Dark Universe, ISSN 0953-8585, E-ISSN 2212-6864, Vol. 19, s. 124-128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The existence (and abundance) of primordial black holes (PBHs) is governed by the power spectrum of primordial perturbations generated during inflation. So far no PBHs have been observed, and instead, increasingly stringent bounds on their existence at different scales have been obtained. Up until recently, this has been exploited in attempts to constrain parts of the inflationary power spectrum that are unconstrained by cosmological observations. We first point out that the simple translation of the PBH non-observation bounds into constraints on the primordial power spectrum is inaccurate as it fails to include realistic aspects of PBH formation and evolution. We then demonstrate, by studying two examples of uncertainties from the effects of critical and non-spherical collapse, that even though they may seem small, they have important implications for the usefulness of the constraints. In particular, we point out that the uncertainty induced by non-spherical collapse may be much larger than the difference between particular bounds from PBH non-observations and the general maximum cap stemming from the condition Omega <= 1 on the dark-matter density in the form of PBHs. We therefore make the cautious suggestion of applying only the overall maximum dark-matter constraint to models of early Universe, as this requirement seems to currently provide a more reliable constraint, which better reflects our current lack of detailed knowledge of PBH formation. These, and other effects, such as merging, clustering and accretion, may also loosen constraints from non-observations of other primordial compact objects such as ultra-compact minihalos of dark matter. 

  • 2. Arguedas Cuendis, S.
    et al.
    Baier, J.
    Barth, K.
    Baum, Sebastian
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA.
    Bayirli, A.
    Belov, A.
    Bräuninger, H.
    Cantatore, G.
    Carmona, J. M.
    Castel, J. F.
    Cetin, S. A.
    Dafni, T.
    Davenport, M.
    Dermenev, A.
    Desch, K.
    Döbrich, B.
    Fischer, H.
    Funk, W.
    García, J. A.
    Gardikiotis, A.
    Garza, J. G.
    Gninenko, S.
    Hasinoff, M. D.
    Hoffmann, D. H. H.
    Iguaz, F. J.
    Irastorza, I. G.
    Jakovčić, K.
    Kaminski, J.
    Karuza, M.
    Krieger, C.
    Lakić, B.
    Laurent, J. M.
    Luzón, G.
    Maroudas, M.
    Miceli, L.
    Neff, S.
    Ortega, I.
    Ozbey, A.
    Pivovaroff, M. J.
    Rosu, M.
    Ruz, J.
    Chóliz, E. R.
    Schmidt, S.
    Schumann, M.
    Semertzidis, Y. K.
    Solanki, S. K.
    Stewart, L.
    Tsagris, I.
    Vafeiadis, T.
    Vogel, J. K.
    Vretenar, M.
    Yildiz, S. C.
    Zioutas, K.
    First results on the search for chameleons with the KWISP detector at CAST2019Ingår i: Physics of the Dark Universe, ISSN 0953-8585, E-ISSN 2212-6864, Vol. 26, artikel-id 100367Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on a first measurement with a sensitive opto-mechanical force sensor designed for the direct detection of coupling of real chameleons to matter. These dark energy candidates could be produced in the Sun and stream unimpeded to Earth. The KWISP detector installed on the CAST axion search experiment at CERN looks for tiny displacements of a thin membrane caused by the mechanical effect of solar chameleons. The displacements are detected by a Michelson interferometer with a homodyne readout scheme. The sensor benefits from the focusing action of the ABRIXAS X-ray telescope installed at CAST, which increases the chameleon flux on the membrane. A mechanical chopper placed between the telescope output and the detector modulates the incoming chameleon stream. We present the results of the solar chameleon measurements taken at CAST in July 2017, setting an upper bound on the force acting on the membrane of 80pN at 95% confidence level. The detector is sensitive for direct coupling to matter 104≤βm≤108, where the coupling to photons is locally bound to βγ≤1011.

  • 3.
    Di Valentino, E.
    et al.
    Jodrell Bank Center for Astrophysics, School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom.
    Ferreira, R. Z.
    Nordita, KTH Royal Institute of Technology and Stockholm University, Roslagstullsbacken 23, Stockholm, 10691, Sweden.
    Visinelli, L.
    KTH, Centra, Nordic Institute for Theoretical Physics NORDITA. Nordita, Stockholm University, Roslagstullsbacken 23, Stockholm, 10691, Sweden cDepartment of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, Uppsala, 75120, Sweden dGravitation Astroparticle Physics Amsterdam (GRAPPA), Institute for Theoretical Physics Amsterdam and Delta Institute for Theoretical Physics, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, Netherlands.
    Danielsson, U.
    Department of Physics and Astronomy, Uppsala University, Lägerhyddsvägen 1, Uppsala, 75120, Swed.
    Late time transitions in the quintessence field and the H0 tension2019Ingår i: Physics of the Dark Universe, ISSN 0953-8585, E-ISSN 2212-6864, Vol. 26, artikel-id 100385Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We consider a quintessence field which transitions from a matter-like to a cosmological constant behaviour between recombination and the present time. We aim at easing the tension in the measurement of the present Hubble rate, and we assess the ΛCDM model properly enlarged to include our quintessence field against cosmological observations. The model does not address the scope we proposed. This result allows us to exclude a class of quintessential models as a solution to the tension in the Hubble constant measurements.

1 - 3 av 3
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf