Results 41 to 50 of about 7,599,029 (258)
Spacetime as a Complex Network and the Cosmological Constant Problem
Universe, 2023 We propose a promising model of discrete spacetime based on nonassociative geometry and complex networks. Our approach treats space as a simplicial 3-complex (or complex network), built from “atoms” of spacetime and entangled states forming n-dimensional
Alexander Nesterov
doaj +1 more source
Is the Zero-Point Energy Real? [PDF]
, 2002 I consider the arguments to show that the vacuum energy density should receive a large contribution from the zero-point energy. This is the cosmological constant problem, as it was originally framed. I suggest that the matter is interpretation-dependent,
Simon Saunders, Saunders, Simon
core +1 more source
CPTM Discrete Symmetry, Quantum Wormholes and Cosmological Constant Problem
Universe, 2020 We discuss the consequences of the charge, parity, time, and mass (CPTM) extended reversal symmetry for the problems of the vacuum energy density and value of the cosmological constant.
Sergey Bondarenko
doaj +1 more source
Vacuum fluctuation, microcyclic universes, and the cosmological constant problem [PDF]
Physical Review D, 2019 We point out that the standard formulation of the cosmological constant problem itself is problematic since it is trying to apply the very large scale homogeneous cosmological model to very small (Planck) scale phenomenon.
Qingdi Wang, W. Unruh
semanticscholar +1 more source
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
core +1 more source
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
Can the fluctuations of the quantum vacuum solve the cosmological constant problem? [PDF]
Physical Review D, 2018 The cosmological constant problem arises because the magnitude of vacuum energy density predicted by quantum mechanics is about 120 orders of magnitude larger than the value implied by cosmological observations of accelerating cosmic expansion. Recently,
Samuel S. Cree +5 more
semanticscholar +1 more source
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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Vacuum energy and the cosmological constant problem in κ -Poincaré invariant field theories [PDF]
Physical Review D, 2018 We investigate the vacuum energy in κ-Poincare invariant field theories. It is shown that for the equivariant Dirac operator one obtains an improvement in UV behavior of the vacuum energy and therefore the cosmological constant problem has to be revised.
Tajron Juri'c +2 more
semanticscholar +1 more source