English
Related papers

Related papers: Regularizing cosmological singularities by varying…

200 papers

A novel approach to quantization is shown to allow for superpositions of the cosmological constant in isotropic and homogeneous mini-superspace models. Generic solutions featuring such superpositions display unitary evolution and resolution…

General Relativity and Quantum Cosmology · Physics 2018-08-15 Sean Gryb , Karim P. Y. Thébault

The Cosmological Constant Problem emerges when Quantum Field Theory is applied to the gravitational theory, due to the enormous magnitude of the induced energy of the vacuum. The unique known solution of this problem involves an extremely…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ilya L. Shapiro , Joan Sola

We consider further consequences of recently [1] revealed role of cosmological constant \Lambda as of a physical constant, along with the gravitational one to define the gravity i.e. the General Relativity and its low-energy limit. We now…

General Physics · Physics 2019-03-13 V. G. Gurzadyan , A. Stepanian

We have critically compared different approaches to the cosmological constant problem, which is at the edge of elementary particle physics and cosmology. This problem is deeply connected with the difficulties formulating a theory of quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Stefan Nobbenhuis

We review a few off-the-beaten-track ideas in cosmology. They solve a variety of fundamental problems; also they are fun. We start with a description of non-singular dilaton cosmology. In these scenarios gravity is modified so that the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert H. Brandenberger , Joao Magueijo

The issue of the cosmological constant is discussed in details and a solution to the problem is suggested.

Astrophysics · Physics 2009-11-07 Moshe Carmeli

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

We discuss how the modifications of the standard Einstein's equations needed to support the cosmological bounce can at the same time lead to vanishing of the well known cosmological constant problem, while also studying the effects of…

General Relativity and Quantum Cosmology · Physics 2025-01-24 Petar Pavlović , Marko Sossich

We define the flatness and quasi-flatness problems in cosmological models. We seek solutions to both problems in homogeneous and isotropic Brans-Dicke cosmologies with varying speed of light. We formulate this theory and find perturbative,…

Astrophysics · Physics 2008-11-26 John D. Barrow , Joao Magueijo

This thesis is concerned with global properties of those cosmological solutions of Einstein's field equations which obey accelerated expansion into the future driven by a non-vanishing cosmological constant, as suggested by current…

General Relativity and Quantum Cosmology · Physics 2007-10-24 Florian Beyer

We discuss the cosmological constant problem, at the minisuperspace level, within the framework of the so-called normalized general relativity (NGR). We prove that the Universe cannot be closed, and reassure that the accompanying…

General Relativity and Quantum Cosmology · Physics 2014-02-03 Aharon Davidson , Shimon Rubin

We reexamine the cosmological constant problem in a finite temperature setup and propose an intriguing possibility of carrying out perturbative analysis by employing a renormalization scheme in which the renormalized Higgs mass (or resummed…

High Energy Physics - Phenomenology · Physics 2022-12-16 I. Y. Park

We have found that proposals addressing the old cosmological constant problem come in various categories. The aim of this paper is to identify as many different, credible mechanisms as possible and to provide them with a code for future…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Stefan Nobbenhuis

The standard $\Lambda$CDM model despite its agreement with observational data still has some issues unaddressed, lie the problem of initial singularity. Solving that problem usually requires modifications of general relativity. However,…

General Relativity and Quantum Cosmology · Physics 2023-03-29 Ewa Czuchry

The standard big bang cosmology has been greatly successful in explaining many observational aspects of the real universe. However, two particular diffficulties faced by it are the so-called ``horizon'' and ``flatness'' problems. By…

General Physics · Physics 2007-05-23 Abhas Mitra

The cosmological constant problem represents an evident tension between our present description of gravity and particle physics. Many solutions have been proposed, but experimental tests are always difficult or impossible to perform and…

High Energy Physics - Phenomenology · Physics 2014-11-18 Cosimo Bambi

A non-commutative multi-dimensional cosmological model is introduced and used to address the issues of compactification and stabilization of extra dimensions and the cosmological constant problem. We show that in such a scenario these…

High Energy Physics - Theory · Physics 2009-11-11 N. Khosravi , S. Jalalzadeh , H. R. Sepangi

We discuss the cosmological constant problem in the light of dilatation symmetry and its possible anomaly. For dilatation symmetric quantum theories realistic asymptotic cosmology is obtained provided the effective potential has a…

High Energy Physics - Theory · Physics 2017-11-13 C. Wetterich

These notes present a brief introduction to `naturalness' problems in cosmology, and to the Cosmological Constant Problem in particular. The main focus is the `old' cosmological constant problem, though the more recent variants are also…

High Energy Physics - Theory · Physics 2013-09-18 C. P. Burgess

The typical scalar field theory has a cosmological constant problem. We propose a generic mechanism by which this problem is avoided at tree level by embedding the theory into a larger theory. The metric and the scalar field coupling…

High Energy Physics - Phenomenology · Physics 2012-07-11 Roman V. Buniy , Thomas W. Kephart