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We first review the cosmological constant problem, and then mention a conjecture of Feynman according to which the general relativistic theory of gravity should be reformulated in such a way that energy does not couple to gravity. We point…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Murat Özer

We study gravitational properties of vacuum energy by erecting a geometry on the stress-energy tensor of vacuum, matter and radiation. Postulating that the gravitational effects of matter and radiation can be formulated by an appropriate…

High Energy Physics - Theory · Physics 2011-07-05 Durmus A. Demir

The cosmological constant problem is explained by a theory based on the discrete space-time hypothesis. The calculated cosmological constant value is of the order of 10^-52[m]^-2 or equivalent to about 0.7 of the critical mass density. It…

Astrophysics · Physics 2007-05-23 H. M. Mok

In applications of Einstein gravity one replaces the quantum-mechanical energy-momentum tensor of sources such as the degenerate electrons in a white dwarf or the black-body photons in the microwave background by c-number matrix elements.…

High Energy Physics - Theory · Physics 2017-11-22 Philip D. Mannheim

I argue that a solution to the cosmological constant problem is to assume that the expectation value of the quantum vacuum stress-energy tensor is proportional to the metric tensor with a negative energy density and positive pressure. This…

General Physics · Physics 2018-05-09 Emilio Santos

Most of the calculations done to obtain the value of the cosmological constant use methods of quantum gravity, a theory that has not been established as yet, and a variety of results are usually obtained. The numerical value of the…

Astrophysics · Physics 2007-05-23 Moshe Carmeli

A new approach to the cosmological constant problem is proposed by modifying Einstein's theory of general relativity, using instead a scalar-tensor theory of gravitation. This theory of gravity crucially incorporates the concept of quantum…

General Relativity and Quantum Cosmology · Physics 2011-10-28 Thomas L. Wilson

The cosmological constant is not an absolute constant. The gravitating part of the vacuum energy is adjusted to the energy density of matter and to other types of the perturbations of the vacuum. We discuss how the vacuum energy responds…

General Relativity and Quantum Cosmology · Physics 2007-05-23 G. E. Volovik

We define, by an integral of geometric quantities over a spherical shell of arbitrary radius, an invariant gravitational entropy. This definition relies on defining a gravitational energy and pressure, and it reduces at the horizon of both…

High Energy Physics - Theory · Physics 2015-06-03 Ram Brustein , A. J. M. Medved

The cosmological constant problem is the principal obstacle in the attempt to interpret dark energy as the quantum vacuum energy. We suggest that the obstacle can be removed, i.e. that the cosmological constant problem can be resolved by…

General Physics · Physics 2012-01-24 Dragan Slavkov Hajdukovic

In this paper we provide both a diagnosis and resolution of the cosmological constant problem, one in which a large (as opposed to a small) cosmological constant $\Lambda$ can be made compatible with observation. We trace the origin of the…

Astrophysics · Physics 2009-10-31 Philip D. Mannheim

We trace the origin of the cosmological constant problem to the assumption that Newton's constant $G$ sets the scale for cosmology. And then we show that once this assumption is relaxed, the very same cosmic acceleration which has served to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Philip D. Mannheim

We investigate the gravitational property of the quantum vacuum by treating its large energy density predicted by quantum field theory seriously and assuming that it does gravitate to obey the equivalence principle of general relativity. We…

General Relativity and Quantum Cosmology · Physics 2019-04-22 Qingdi Wang , Zhen Zhu , William G. Unruh

The cosmological constant problem is one of the greatest challenges in contemporary physics, since it is deeply rooted in the problematic interplay between quantum fields and gravity. The aim of this work is to review the key conceptual…

General Relativity and Quantum Cosmology · Physics 2025-04-23 Federico Scali

Based on the assertion that the cosmological constant problem is essentially a quantum gravity problem, the framework which addresses the cosmological constant problem should also bear a picture for the ``quantum space-time''. In this talk…

High Energy Physics - Phenomenology · Physics 2009-10-07 M. M. Sheikh-Jabbari

An accelerated universe should naturally have a vacuum energy density determined by its dynamical curvature. The cosmological constant is most likely a temporary description of a dynamical variable that has been drastically evolving from…

General Relativity and Quantum Cosmology · Physics 2015-10-28 Joan Sola

The trace-free version of the Einstein Gravitational equations, essentially equivalent to unimodular gravity, can solve the troubling issue of the huge discrepancy between quantum field theory estimates of the vacuum energy density and the…

General Relativity and Quantum Cosmology · Physics 2014-12-31 George F R Ellis

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…

General Relativity and Quantum Cosmology · Physics 2022-10-14 The FADE Collaboration , Heliudson Bernardo , Benjamin Bose , Guilherme Franzmann , Steffen Hagstotz , Yutong He , Aliki Litsa , Florian Niedermann

We propose a solution to the longstanding cosmological constant (CC) problem which is based on the fusion of two existing concepts. The first is the suggestion that the proper description of classical gravitational effects is the gauge…

General Relativity and Quantum Cosmology · Physics 2011-09-05 Pisin Chen

We consider a Lorentz-violating theory of gravity where the aether vector is taken to be nondynamical. This "ponderable aether theory" is almost the same as Einstein-aether theory (where the aether vector is dynamical), but involves…

General Relativity and Quantum Cosmology · Physics 2015-08-19 Antony J. Speranza