English
Related papers

Related papers: Cosmological Constant from Equivalent Transformati…

200 papers

We provide a new perspective on the cosmological constant by exploring the background-independent Wheeler-DeWitt quantization of general relativity. The Chern-Simons-Kodama state of quantum gravity, a generalization of the Hartle-Hawking…

General Relativity and Quantum Cosmology · Physics 2025-06-19 Stephon Alexander , Heliudson Bernardo , Aaron Hui

We propose an approach to quantum cosmology of integrable models. To analyze the models with two dynamical variables, we introduce equivalent Hamiltonians in reduced phase spaces, which are obtained with the aid of the Faddeev--Jackiw…

General Relativity and Quantum Cosmology · Physics 2020-05-11 Nahomi Kan , Masashi Kuniyasu , Kiyoshi Shiraishi , Kohjiroh Takimoto

Quantum cosmology in general denotes the application of quantum physics to the whole universe and thus gives rise to many realizations and examples, covering problems at different mathematical and conceptual levels. It is related to quantum…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

We discuss how to extract information about the cosmological constant from the Wheeler-DeWitt equation, considered as an eigenvalue of a Sturm-Liouville problem in a generic spherically symmetric background. The equation is approximated to…

General Relativity and Quantum Cosmology · Physics 2015-05-19 Remo Garattini

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

The importance of the tomographic approach is that either in quantum mechanics as in classical mechanics the state of a physical system is expressed with the same family of functions, the tomograms. The extension of this procedure to…

General Relativity and Quantum Cosmology · Physics 2019-01-30 Cosimo Stornaiolo

We discuss how to extract information about the cosmological constant from the Wheeler-DeWitt equation, considered as an eigenvalue of a Sturm-Liouville problem. A generalization to a f(R)theory is taken under examination. The equation is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Remo Garattini

At the level of the Planck scale, the spacetime metric has to be considered a quantum variable. Conformal quantum fluctuations of the metric tensor are studied here. They lead to an extra term in the Einstein equations which can be…

Astrophysics · Physics 2007-05-23 Alex H. Blin

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

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

Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and…

High Energy Physics - Theory · Physics 2013-05-29 Grant Larsen , Yasunori Nomura , H. L. L. Roberts

The cosmological constant problem is one of the long-standing issues of modern physics. While we can measure the value of the cosmological constant with great accuracy, we are not able to calculate it in a coherent theoretical framework. On…

High Energy Physics - Theory · Physics 2012-09-21 Simone Zonetti

A diverse set of observations now compellingly suggest that Universe possesses a nonzero cosmological constant. In the context of quantum-field theory a cosmological constant corresponds to the energy density of the vacuum, and the wanted…

Astrophysics · Physics 2014-10-13 Lawrence M. Krauss , Michael S. Turner

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

We propose a time-varying cosmological constant with a fixed equation of state, which evolves mainly through its interaction with the background during most of the long history of the universe. However, such interaction does not exist in…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-18 Murli Manohar Verma

Various contributions to the cosmological constant are discussed and confronted with its recent measurement. We briefly review different scenarious -- and their difficulties -- for a solution of the cosmological constant problem.

High Energy Physics - Phenomenology · Physics 2017-08-23 U. Ellwanger

The work shows that the associated Einstein like gravity for the Klein-Gordon field shows the spontaneous emergence of the cosmological pressure tensor density (CPTD) that in the classical limit leads to the cosmological constant (CC). Even…

General Physics · Physics 2020-07-07 Piero Chiarelli

We take another look at the equations behind the description of light bending in a Universe with a cosmological constant. We show that even within the impact parameter entering into the photon's differential equation, and which is defined…

General Relativity and Quantum Cosmology · Physics 2015-08-17 Fayçal Hammad

We study a Newtonian cosmological model in the context of a noncommutative space. It is shown that the trajectories of a test particle undergo modifications such that it no longer satisfies the cosmological principle. For the case of a…

High Energy Physics - Theory · Physics 2010-11-05 Juan M. Romero , J. A. Santiago

We consider a simple modification of the amplitude defining the dynamics of loop quantum gravity, corresponding to the introduction of the cosmological constant, and possibly related to the SL(2,C)q extension of the theory recently…

General Relativity and Quantum Cosmology · Physics 2011-05-13 Eugenio Bianchi , Thomas Krajewski , Carlo Rovelli , Francesca Vidotto