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Related papers: Bounce Cosmologies in Generalized Coupling Theorie…

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We introduce the "wedge diagram," an intuitive way to illustrate how cosmological models with a classical (non-singular) bounce generically resolve fundamental problems in cosmology. These include the well-known horizon, flatness, and…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-27 Anna Ijjas , Paul J. Steinhardt

Cosmological models involving a bounce from a contracting to an expanding universe can address the standard cosmological puzzles and generate "primordial" density perturbations without the need for inflation. Some such models, in particular…

High Energy Physics - Theory · Physics 2015-05-28 Jean-Luc Lehners

A companion paper provides a proposal for cosmic singularity resolution based upon general features of a bouncing unitary cosmological model in the mini-superspace approximation. This paper analyses novel phenomenology that can be…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

We offer a new proposal for cosmic singularity resolution based upon a quantum cosmology with a unitary bounce. This proposal is illustrated via a novel quantization of a mini-superspace model in which there can be superpositions of the…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

In this paper, we model the bounce phase, stability, and the reconstruction of the universe by non-minimal kinetic coupling. In the process, we obtained importance information about the energy density and the matter pressure of the universe…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Alireza Amani , A. S. Kubeka , E. Mahichi

We review the general features of nonsingular universes ({\em i.e.} those that go from an era of accelerated collapse to an expanding era without displaying a singularity) as well as cyclic universes. We discuss the mechanisms behind the…

Astrophysics · Physics 2008-12-18 M. Novello , S. E. Perez Bergliaffa

Background boucing cosmologies in the framework of General Relativity, driven by a single scalar field filling the Universe, and with a quasi-matter domination period, i.e., depicting the so-called Matter Bounce Scenario, are reconstructed…

General Relativity and Quantum Cosmology · Physics 2017-03-22 Jaume de Haro

We present a rich class of exact solutions which contains radiation-dominated and matter-dominated models for the early and late universe. They include a variable cosmological ``constant'' which is derived from a higher dimension and…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Hongya Liu , Paul S. Wesson

A bouncing cosmology with an initial matter-dominated phase of contraction during which scales which are currently probed with cosmological observations exit the Hubble radius provides a mechanism alternative to inflation for producing a…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-20 Robert H. Brandenberger

We explicitly confirm that spatially flat non-singular bouncing cosmologies make sense as effective theories. The presence of a non-singular bounce in a spatially flat universe implies a temporary violation of the null energy condition,…

High Energy Physics - Theory · Physics 2016-05-11 Michael Koehn , Jean-Luc Lehners , Burt Ovrut

Quantum cosmology in the presence of a fundamental minimal length is analyzed in the context of the flat isotropic and the Taub cosmological models. Such minimal scale comes out from a generalized uncertainty principle and the quantization…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marco Valerio Battisti , Giovanni Montani

We propose a new cosmological paradigm in which our observed expanding phase is originated from an initially large contracting Universe that subsequently experienced a bounce. This category of models, being geodesically complete, is…

General Relativity and Quantum Cosmology · Physics 2008-11-07 Patrick Peter , Nelson Pinto-Neto

Bouncing cosmologies, suggested by String/M-theory, may provide an alternative to standard inflation to account for the origin of inhomogeneities in our universe. The fundamental question regards the correct way to evolve the scalar…

High Energy Physics - Theory · Physics 2009-11-11 V. Bozza

We present a bounce universe in modified $f(Q,C)$ gravity considering linear as well as exponential form of gravity. Bounce cosmological models are introduced to remove the singularity problem of the early universe. A new quadratic boundary…

General Relativity and Quantum Cosmology · Physics 2025-08-07 Bhaswati Mandal , B. C. Paul

We investigate cosmological models with a linear inhomogeneous time-dependent equation of state for the dark energy, coupled with dark matter, leading to a bounce cosmology. Equivalent descriptions in terms of the equation-of-state…

General Relativity and Quantum Cosmology · Physics 2014-05-07 I. Brevik , V. V. Obukhov , A. V. Timoshkin

The main objective of this article is to investigate the viability of bouncing cosmological scenarios using different forms of scale factors with perfect matter configuration in the framework of extended symmetric teleparallel theory. This…

General Relativity and Quantum Cosmology · Physics 2024-07-31 M. Zeeshan Gul , M. Sharif , Shamraiza Shabbir

We propose a set of equations as a simple model for non singular evolutions of a $10 + 1$ dimensional M theory universe. Our model uses ideas from Loop Quantum Cosmology and offers a solution to the important problem of singularity…

High Energy Physics - Theory · Physics 2020-02-25 Saroj Prasad Chhatoi , S. Kalyana Rama

The present work analyzes the various conditions in which there can be a bouncing universe solution in f(R) gravity. In the article an interesting method, to analyze the bouncing FRW solutions in a spatially flat universe using f(R) gravity…

General Relativity and Quantum Cosmology · Physics 2014-12-09 Niladri Paul , Saikat Nil Chakrabarty , Kaushik Bhattacharya

Following up an earlier suggestion of how the Tolman Entropy Conundrum (TEC) can be solved in a cyclic cosmology using the Come Back Empty (CBE) assumption with phantom dark energy, here we show how the same CBE strategy may work with a…

General Relativity and Quantum Cosmology · Physics 2014-12-01 Paul H. Frampton

A bouncing scenario of a flat homogeneous and isotropic universe is explored by using the reconstruction technique for the power-law parametrization of the Hubble parameter in a modified gravity theory with higher-order curvature and trace…

General Relativity and Quantum Cosmology · Physics 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena
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