Results 11 to 20 of about 1,305 (201)
Cosmological Bounce and the Cosmological Constant Problem
SSRN Electronic Journal, 2022 32 pages, 9 ...
Pavlović, Petar, Sossich, Marko
openaire +3 more sources
THE NATURE OF THE COSMOLOGICAL CONSTANT PROBLEM [PDF]
International Journal of Modern Physics A, 2009 General relativity postulates the Minkowski space-time as the standard (flat) geometry against which we compare all curved space-times and also as the gravitational ground state where particles, quantum fields and their vacua are defined. On the other hand, experimental evidences tell that there exists a non-zero cosmological constant, which implies ...
Maia, M. D. +2 more
openaire +2 more sources
Superfluids and the cosmological constant problem [PDF]
Journal of Cosmology and Astroparticle Physics, 2018 We introduce a novel method to circumvent Weinberg's no-go theorem for self-tuning the cosmological vacuum energy: a Lorentz-violating finite-temperature superfluid can counter the effects of an arbitrarily large cosmological constant. Fluctuations of the superfluid result in the graviton acquiring a Lorentz-violating mass and we identify a unique ...
Khoury, Justin +2 more
openaire +3 more sources
A NOVEL APPROACH TO THE COSMOLOGICAL CONSTANT PROBLEM [PDF]
International Journal of Modern Physics A, 2004 We propose a novel infinite-volume brane world scenario where we live on a noninflating spherical 3-brane, whose radius is somewhat larger than the present Hubble size, embedded in higher dimensional bulk. Once we include higher curvature terms in the bulk, we find completely smooth solutions with the property that the 3-brane world-volume is ...
Iglesias, Alberto, Kakushadze, Zurab
openaire +3 more sources
New Solution of the Cosmological Constant Problems [PDF]
Physical Review Letters, 2011 We extend the usual gravitational action principle by promoting the bare cosmological constant (CC) from a parameter to a field which can take many possible values. Variation leads to a new integral constraint equation which determines the classical value of the effective CC that dominates the wave function of the universe.
Barrow, John D., Shaw, Douglas J.
openaire +3 more sources
Problems with the Cosmological Constant Problem [PDF]
, 2021 The cosmological constant problem is widely viewed as an important barrier and hint to merging quantum field theory and general relativity. It is a barrier insofar as it remains unsolved, and a solution may hint at a fuller theory of quantum gravity. I critically examine the arguments used to pose the cosmological constant problem, and find many of the
openaire +1 more source
A SOLUTION TO THE COSMOLOGICAL CONSTANT PROBLEM [PDF]
International Journal of Modern Physics D, 2005 According to general relativity, the present analysis shows on geometrical grounds that the cosmological constant problem is an artifact due to the unfounded link of this fundamental constant to vacuum energy density of quantum fluctuations.
openaire +2 more sources
Vacuum Energy, the Casimir Effect, and Newton’s Non-Constant
Universe, 2023 The idea of quantum mechanical vacuum energy contributing to the cosmological vacuum energy density is not new. However, despite the persisting cosmological constant problem, few investigations have focused on this subject.
Benjamin Koch +3 more
doaj +1 more source
The cosmological constant problem and quintessence [PDF]
Classical and Quantum Gravity, 2002 I briefly review the cosmological constant problem and the issue of dark energy (or quintessence). Within the framework of quantum field theory, the vacuum expectation value of the energy momentum tensor formally diverges as $k^4$. A cutoff at the Planck or electroweak scale leads to a cosmological constant which is, respectively, $10^{123}$ or $10^{55}
openaire +3 more sources
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
doaj +1 more source