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Related papers: Bang or Bounce

200 papers

The problem of understanding how a coherent, macroscopic Bose-Einstein condensate (BEC) emerges from the cooling of a thermal Bose gas has attracted significant theoretical and experimental interest over several decades. The pioneering…

Universe structure emerges in the unreduced, complex-dynamic interaction process with the simplest initial configuration (two attracting homogeneous fields, quant-ph/9902015). The unreduced interaction analysis gives intrinsically creative…

General Physics · Physics 2007-05-23 Andrei P. Kirilyuk

In loop quantum cosmology (LQC) the big bang is replaced by a quantum bounce which is followed by a robust phase of super-inflation. Rather than growing unboundedly in the past, the Hubble parameter \emph{vanishes} at the bounce and attains…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Abhay Ashtekar , David Sloan

In [1], KKLT give a mechanism to generate de Sitter vacua in string theory. And the scenario, \emph{Landscape}, is suggested to explain the problem of the cosmological constant. In this paper, adopting a simple potential describing the…

High Energy Physics - Theory · Physics 2007-05-23 Cheng-Yi Sun , De-Hai Zhang

It is demonstrated that entropy and its density play a significant role in solving the problem of the vacuum energy density (cosmological constant) of the Universe and hence the dark energy problem. Taking this in mind, two most popular…

General Relativity and Quantum Cosmology · Physics 2011-04-07 A. E. Shalyt-Margolin

A matter bouncing entropy-corrected cosmological model has been suggested. The model allows only positive curvature with negative pressure and no violation of the null energy condition. The result obtained in this paper is supported by some…

General Relativity and Quantum Cosmology · Physics 2022-10-12 Nasr Ahmed , Tarek M. Kamel , Mohamed I Nouh

Loop quantum cosmology homogeneous models with a massless scalar field show that the big-bang singularity can be replaced by a big quantum bounce. To gain further insight on the nature of this bounce, we study the semi-discrete loop quantum…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Pablo Laguna

We introduce a string-inspired model for a bouncing/cyclic universe, utilizing the scalar-tachyon coupling as well as contribution from curvature in a closed universe. The universe undergoes the locked inflation, tachyon matter dominated…

General Relativity and Quantum Cosmology · Physics 2014-01-22 Changhong Li , Lingfei Wang , Yeuk-Kwan E. Cheung

Using only the standard considerations of spacetime foam and the Euclidean Quantum Gravity techniques known long ago, we result to a model of Topological Dark Energy (TDE) that outperforms the standard $\Lambda$CDM paradigm with regard to…

General Relativity and Quantum Cosmology · Physics 2025-07-25 Fotios K. Anagnostopoulos , Stylianos A. Tsilioukas , Emmanuel N. Saridakis

We analyze the dynamics of a homogeneous and isotropic universe in the Einstein$--$Cartan theory of gravity. The coupling between the spin and torsion prevents gravitational singularities and replaces the Big Bang with a nonsingular big…

General Relativity and Quantum Cosmology · Physics 2019-03-05 Gabriel Unger , Nikodem Popławski

We investigate the emergence of cosmic hysteresis in cyclic bouncing cosmologies within the framework of $f(R)$ modified gravity theories. Building upon previous studies that explored hysteresis phenomena in braneworld and…

General Relativity and Quantum Cosmology · Physics 2025-06-12 Aritra Sanyal

The coupling between spin and torsion in the Einstein-Cartan-Sciama-Kibble theory of gravity generates gravitational repulsion at very high densities, which prevents a singularity in a black hole and may create there a new universe. We show…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-22 Shantanu Desai , Nikodem J. Poplawski

Alternative scenarios to the Big Bang singularity have been subject of intense research for several decades by now. Most popular in this sense have been frameworks were such singularity is replaced by a bounce around some minimal…

General Relativity and Quantum Cosmology · Physics 2017-09-25 Emanuele Alesci , Gioele Botta , Francesco Cianfrani , Stefano Liberati

The dynamics of an inhomogeneous universe is studied with the methods of Loop Quantum Cosmology as an example of the quantization of vacuum cosmological spacetimes containing gravitational waves (Gowdy spacetimes). The analysis performed at…

General Relativity and Quantum Cosmology · Physics 2010-02-17 David Brizuela , Guillermo A. Mena Marugan , Tomasz Pawlowski

For two decades the hot big-bang model as been referred to as the standard cosmology -- and for good reason. For just as long cosmologists have known that there are fundamental questions that are not answered by the standard cosmology and…

Astrophysics · Physics 2009-10-31 Michael S. Turner

We examine the dynamics of a closed cosmology whose matter source is that of a conformally coupled scalar field with a broken ${\rm SO}(1,1)$ symmetry, which correspond to the $\alpha$-attractors proposed by Linde and Kallosh. Following a…

General Relativity and Quantum Cosmology · Physics 2020-02-19 David Sloan , Konstantinos Dimopoulos , Sotirios Karamitsos

A scalar-tensor theory of gravity is formulated in which $G$ and particle masses are allowed to vary. The theory yields a globally static cosmological model with no evolutionary timescales, no cosmological coincidences, and no flatness and…

General Physics · Physics 2015-10-01 Meir Shimon

We present a model of the expanding Universe that begins in a zero energy vacuum state. The Universe results from the spontaneous breaking of the electroweak symmetry, wherein the vacuum with positive expectation energy produces the dark…

General Physics · Physics 2021-04-29 R. N. Henriksen

The sequestering mechanism has been proposed as a remedy to the old cosmological constant problem of the non-gravitating vacuum energy in the matter sector. Here it is shown that an extension of this global constraint mechanism arises…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-01 Lucas Lombriser

In a recent Foundations of Physics paper [5] by the current author it was shown that, when the self-force problem of classical electrodynamics is properly solved, it becomes a plausible ontology underlying the statistical description of…

General Physics · Physics 2021-03-09 Yehonatan Knoll