Results 61 to 70 of about 4,839,190 (320)
Cosmology with varying constants [PDF]
Philosophical Transactions of the Royal Society of London. Series A: Mathematical, Physical and Engineering Sciences, 2001 14 pages, no figures. Essay to appear in Phil. Trans. Roy. Soc. Lond. A Triennial Series (Christmas 2002 Issue)
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Shadow and deflection angle of rotating black holes in perfect fluid dark matter with a cosmological constant [PDF]
Physical Review D, 2018 The presence of dark matter around a black hole remarkably affects its spacetime. We consider the effects of dark matter on the shadow of a new solution to the Einstein equations that describes a rotating black hole in the background of perfect dark ...
Sumarna Haroon +4 more
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Unified Dark Matter models with fast transition [PDF]
, 2010 We investigate the general properties of Unified Dark Matter (UDM) fluid models where the pressure and the energy density are linked by a barotropic equation of state (EoS) p = p(ρ) and the perturbations are adiabatic.
Davide Pietrobon +12 more
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Cosmological constant: Relaxation vs multiverse
Physics Letters B, 2019 We consider a scalar field with a bottom-less potential, such as g3ϕ, finding that cosmologies unavoidably end up with a crunch, late enough to be compatible with observations if g≲1.2H02/3MPl1/3. If rebounces avoid singularities, the multiverse acquires
Alessandro Strumia, Daniele Teresi
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Lifshitz theory of the cosmological constant [PDF]
Annals of Physics, 2019 Astrophysics has given empirical evidence for the cosmological constant that accelerates the expansion of the universe. Atomic, Molecular, and Optical Physics has proven experimentally that the quantum vacuum exerts forces - the van der Waals and Casimir
U. Leonhardt
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Wormholes and the cosmological constant [PDF]
Nuclear Physics B, 1989 We review Coleman's wormhole mechanism for the vanishing of the cosmological constant. We show that in a minisuperspace model wormhole-connected universes dominate the path integral. We also provide evidence that the euclidean path integral over geometries with spherical topology is unstable with respect to formation of infinitely many wormhole ...
Igor KLEBANOV +2 more
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Universe, 2020 The stage of a super-early (primordial) scale-invariant Universe is considered on the basis of the Poincaré–Weyl gauge theory of gravity in a Cartan–Weyl space-time. An approximate solution has been found that demonstrates an inflationary behavior of the
Ol’ga Babourova, Boris Frolov
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The Atacama Cosmology Telescope: DR6 Gravitational Lensing Map and Cosmological Parameters [PDF]
Astrophysical Journal, 2023 We present cosmological constraints from a gravitational lensing mass map covering 9400 deg2 reconstructed from measurements of the cosmic microwave background (CMB) made by the Atacama Cosmology Telescope (ACT) from 2017 to 2021.
M. Madhavacheril +158 more
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Cosmology Intertwined: A Review of the Particle Physics, Astrophysics, and Cosmology Associated with the Cosmological Tensions and Anomalies [PDF]
Journal of High Energy Astrophysics, 2022 In this paper we will list a few important goals that need to be addressed in the next decade, also taking into account the current discordances between the different cosmological probes, such as the disagreement in the value of the Hubble constant $H_0$,
E. Abdalla +202 more
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Proposal for a constant cosmological constant [PDF]
Physics Letters B, 2000 12 pages, LaTeX, 1 figure; minor rewriting, references corrected, results ...
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