Results 1 to 10 of about 197,098 (270)
On the cosmological constant problem
Physics Letters B, 2019 An additional variation of the Einstein-Hilbert action with respect to the Planck mass provides a constraint on the average Ricci scalar that prevents vacuum energy from gravitating. Consideration of the evolution of the inhomogeneous matter distribution
Lucas Lombriser
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Modified gravity with disappearing cosmological constant
Journal of High Energy Physics, 2021 New corrections to General Relativity are considered in the context of modified f(R) gravity, that satisfy cosmological and local gravity constraints. The proposed models behave asymptotically as R − 2Λ at large curvature and show the vanishing of the ...
L. N. Granda
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Graviton fluctuations erase the cosmological constant
Physics Letters B, 2017 Graviton fluctuations induce strong non-perturbative infrared renormalization effects for the cosmological constant. The functional renormalization flow drives a positive cosmological constant towards zero, solving the cosmological constant problem ...
C. Wetterich
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Lemaître Class Dark Energy Model for Relaxing Cosmological Constant
Universe, 2017 Cosmological constant corresponds to the maximally symmetric cosmological term with the equation of state p = − ρ . Introducing a cosmological term with the reduced symmetry, p r = − ρ in the spherically symmetric case, makes ...
Irina Dymnikova +2 more
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European Physical Journal C: Particles and Fields, 2019 The future space-borne detectors will provide the possibility to detect gravitational waves emitted from extreme mass ratio inspirals of stellar-mass compact objects into supermassive black holes.
Yu-Peng Zhang +4 more
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Black hole shadow with a cosmological constant for cosmological observers
European Physical Journal C: Particles and Fields, 2019 We investigate the effect of the cosmological constant on the angular size of a black hole shadow. It is known that the accelerated expansion which is created by the cosmological constant changes the angular size of the black hole shadow for static ...
Javad T. Firouzjaee, Alireza Allahyari
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The history of the Cosmos: Implications for the Hubble tension
Open Astronomy, 2023 In 2007, Storti predicted that the value of the cosmic microwave background radiation (CMBR) temperature may be improved: from the particle data group (PDG) value of [T 0 = 2.725 ± 0.001 K] to [T 0 = 2.7254 K].
Storti Riccardo C.
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A natural cosmological constant from chameleons
Physics Letters B, 2015 We present a simple model where the effective cosmological constant appears from chameleon scalar fields. For a Kachru–Kallosh–Linde–Trivedi (KKLT)-inspired form of the potential and a particular chameleon coupling to the local density, patches of ...
Horatiu Nastase, Amanda Weltman
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Scientific ReportsIn this article, we explicitly construct the coordinates associated with the Penrose diagram in spacetimes connected via a spacelike thin shell in the following two examples: the generalized black-to-white hole bounce with mass difference and the ...
Wei-Chen Lin +2 more
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Running cosmological constant with observational tests
Physics Letters B, 2016 We investigate the running cosmological constant model with dark energy linearly proportional to the Hubble parameter, Λ=σH+Λ0, in which the ΛCDM limit is recovered by taking σ=0. We derive the linear perturbation equations of gravity under the Friedmann–
Chao-Qiang Geng +2 more
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