Results 11 to 20 of about 16,133 (302)
Scholarpedia, 2010 In the context of cosmology the cosmological constant is a homogeneous energy density that causes the expansion of the universe to accelerate. Originally proposed early in the development of general relativity in order to allow a static universe solution it was subsequently abandoned when the universe was found to be expanding.
Davis, Tamara, Griffen, Brendan
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The Quantum Cosmological Constant [PDF]
Symmetry, 2019 We present an extension of general relativity in which the cosmological constant becomes dynamical and turns out to be conjugate to the Chern–Simons invariant of the Ashtekar connection on a spatial slicing. The latter has been proposed Soo and Smolin as a time variable for quantum gravity: the Chern–Simons time.
Stephon Alexander +2 more
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Deconstructing the Cosmological Constant [PDF]
, 2003 Deconstruction provides a novel way of dealing with the notoriously difficult ultraviolet problems of four-dimensional gravity. This approach also naturally leads to a new perspective on the holographic principle, tying it to the fundamental requirements of unitarity and diffeomorphism invariance, as well as to a new viewpoint on the cosmological ...
Jejjala, Vishnu +2 more
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Hiding the Cosmological Constant [PDF]
Physical Review Letters, 2019 9+1 pages; v2: better discussion of evolution,m new references, some rewriting for clarity; v3: even better discussion of evolution, added references, minor ...
Carlip, S,, Carlip, S
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Graviton fluctuations erase the cosmological constant [PDF]
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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Fixing cosmological constant on the event horizon [PDF]
European Physical Journal C: Particles and Fields, 2022 Standard cosmological equations are written for the Hubble volume, while the real boundary of space-time is the event horizon. Within the unimodular and thermodynamic approaches to gravity, the dark energy term in cosmological equations appears as an ...
Merab Gogberashvili
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A natural cosmological constant from chameleons [PDF]
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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Homogeneous cosmologies with a cosmological constant [PDF]
Physical Review D, 1999 Spatially homogeneous cosmological models with a positive cosmological constant are investigated, using dynamical systems methods. We focus on the future evolution of these models. In particular, we address the question whether there are models within this class that are de Sitter-like in the future, but are tilted.
Goliath, Martin, Ellis, George F. R.
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THE VALUE OF THE COSMOLOGICAL CONSTANT [PDF]
International Journal of Modern Physics D, 2011 We make the cosmological constant, Λ, into a field and restrict the variations of the action with respect to it by causality. This creates an additional Einstein constraint equation. It restricts the solutions of the standard Einstein equations and is the requirement that the cosmological wave function possess a classical limit.
Barrow, John D., Shaw, Douglas J.
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Inflation and cosmological constant [PDF]
Physica Scripta, 2021 Abstract In construction of an inflationary model, one usually assumes that the matter sector of the gravitational action is minimally coupled to the background. It means that the matter (inflaton) part of the action is coupled with the same metric of the gravitational part.
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