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We have recently constructed a manifestly local formulation of a nonlocal approach to the cosmological constant problem which can treat with quantum effects from both matter and gravitational fields. In this formulation, it has been…

High Energy Physics - Theory · Physics 2018-05-09 Ichiro Oda

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

I describe an approach which connects classical gravity with the quantum microstructure of spacetime. The field equations arise from maximizing the density of states of matter plus geometry. The former is identified using the thermodynamics…

General Relativity and Quantum Cosmology · Physics 2017-08-25 T. Padmanabhan

A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by large-scale structure formation, thus eliminating the coincidence and magnitude fine-tuning problems of the Cosmological Constant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Brett Bochner

This is an essay sketching the line of thinking which has led the present author to propose the constituent or atomic model of gravitation more than a decade ago. It turns out that viewing the problem of gravitation as a quantum many body…

Astrophysics · Physics 2009-10-19 Pawel O. Mazur

Why the cosmological constant $\Lambda$ observed today is so much smaller than the Planck scale or why the universe is accelerating at present? This is so-called the cosmological constant fine-tuning problem. In this paper, we find that…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-26 Chao-Jun Feng , Xin-Zhou Li

In this work, I develop an alternative explanation for the acceleration of the cosmic expansion, which seems to be a result of recent high redshift Supernova data. In the current interpretation, this cosmic acceleration is explained by…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. -F. Pascual-Sánchez

The problem of the physical nature and the cosmological genesis of Lambda-term is discussed. This problem can't be solved in terms of the current quantum field theory which operates with Higgs and non-perturbative vacuum condensates and…

General Relativity and Quantum Cosmology · Physics 2007-05-23 V. Burdyuzha , O. Lalakulich , G. Vereshkov , Yu. Ponomarev

In this article the cosmological constant problems, as well as the astronomical evidence for a cosmologically significant homogeneous exotic energy density with negative pressure (quintessence), are reviewed for a broad audience of…

Astrophysics · Physics 2007-05-23 Norbert Straumann

Combining general relativity and gravitational gauge theory, the cosmological constant is determined theoretically. The cosmological constant is related to the average vacuum energy of gravitational gauge field. Because the vacuum energy of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Ning Wu , Germano Resconi , Zhan Xu , Zhi-Peng Zheng , Da-Hua Zhang , Tu-Nan Ruan

The quantum field theory prediction of the cosmological constant is 120 orders of magnitude higher than the observed value. This is known as the cosmological constant problem. Here, we deal with the cosmological constant as a scalar field…

High Energy Physics - Theory · Physics 2010-11-29 Nicolas Avilan V. , Jose Rolando Roldan

It is shown here that a dynamical Planck mass can drive the scale factor of the universe to accelerate. The negative pressure which drives the cosmic acceleration is identified with the unusual kinetic energy density of the Planck field. No…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Janna Levin

A phenomenological formalism is presented in which the apparent acceleration of the universe is generated by large-scale structure formation, thus eliminating the magnitude and coincidence fine-tuning problems of the Cosmological Constant…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-14 Brett Bochner

We build a minimal extension of General Relativity in which Newton's gravitational coupling, $G$, the speed of light, $c$, and the cosmological constant, $\Lambda$, are spacetime variables. This is done while satisfying the contracted…

General Relativity and Quantum Cosmology · Physics 2017-04-27 Guilherme Franzmann

In the present article, which is the first part of a work in three parts, we build an equation of quantum gravity. This equation is tensorial, is equivalent to general relativity in vacuum, but differs completely from general relativity…

General Physics · Physics 2007-11-25 Christophe Real

The late time acceleration of the Universe has challenged contemporary cosmology since its discovery. General Relativity explains this phenomenon by introducing the cosmological constant, named the standard cosmological model…

General Relativity and Quantum Cosmology · Physics 2024-01-02 Simran Arora

We study cosmological solutions for the very early universe beginning at the Planck scale for a universe containing radiation, curvature and, as a simplification of a possible scalar field potential, a cosmological constant term. The…

General Relativity and Quantum Cosmology · Physics 2010-01-30 E. Galindo-Dellavalle , G. German , A. de la Macorra

The standard model of cosmology is investigated using time dependent cosmological constant $\Lambda$ and Newton's gravitational constant $G$. The total energy content is described by the modified Chaplygin gas equation of state. It is found…

General Relativity and Quantum Cosmology · Physics 2009-03-12 Mubasher Jamil , Farook Rahaman , Mehedi Kalam

We connect a possible solution for the ``cosmological constant problem'' to the existence of a (postulated) conformal fixed point in a fundamental theory. The resulting cosmology leads to quintessence, where the present acceleration of the…

High Energy Physics - Theory · Physics 2009-11-07 C. Wetterich

This thesis focuses on late-time cosmic acceleration within modified theories of gravity, using various observational data sets and statistical analysis. The Universe is assumed to be spatially homogeneous and isotropic and is described by…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Santosh V. Lohakare