Results 1 to 10 of about 1,305 (201)
Unimodular Approaches to the Cosmological Constant Problem
Universe, 2023 We review selected aspects of unimodular gravity and we discuss its viability as a solution of the old cosmological constant problem. In unimodular gravity, the cosmological constant is promoted to a global degree of freedom.
Pavel Jiroušek
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Modified Gravity Approaches to the Cosmological Constant Problem
Universe, 2023 The cosmological constant and its phenomenology remain among the greatest puzzles in theoretical physics. We review how modifications of Einstein’s general relativity could alleviate the different problems associated with it that result from the ...
Foundational Aspects of Dark Energy (FADE) Collaboration +7 more
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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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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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European Physical Journal C: Particles and Fields, 2022 The renormalization of the vacuum energy in quantum field theory (QFT) is usually plagued with theoretical conundrums related not only with the renormalization procedure itself, but also with the fact that the final result leads usually to very large ...
Cristian Moreno-Pulido +1 more
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Revisiting the Cosmological Constant Problem within Quantum Cosmology
Universe, 2020 A new perspective on the Cosmological Constant Problem (CCP) is proposed and discussed within the multiverse approach of Quantum Cosmology. It is assumed that each member of the ensemble of universes has a characteristic scale a that can be used as ...
Vesselin G. Gueorguiev, Andre Maeder
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Comments on the cosmological constant in generalized uncertainty models
Frontiers in Astronomy and Space Sciences, 2022 The existence of a small, non-zero cosmological constant is one of the major puzzles in fundamental physics. Naively, quantum field theory arguments would imply a cosmological constant which is up to 10,120 times larger than the observed one.
Michael Bishop +3 more
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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
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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
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Solution of the cosmological constant problem within holographic cosmology
Physics Letters B, 2020 Within the holographic cosmology paradigm, specifically the model of McFadden and Skenderis, but more generally than that, the cosmological constant is found to naturally flow from a large value, to a small value, which can even be as low as the needed ...
Horatiu Nastase
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