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Related papers: G-Bounce

200 papers

We explore the possibility of avoiding cosmological singularity with a bounce solution in the early Universe. The main finding is that simple and well-known semiclassical correction, which describes the mixing of radiation and gravity in…

General Relativity and Quantum Cosmology · Physics 2024-10-07 Wagno Cesar e Silva , Ilya L. Shapiro

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 investigate a bounce inflation model with a graceful exit into the Friedmann-Robertson-Walker (FRW) decelerated Universe within $f(T)$ gravity framework, where $T$ is the torsion scalar in the teleparallelism. We study the cosmic thermal…

General Relativity and Quantum Cosmology · Physics 2016-10-13 Kazuharu Bamba , G. G. L. Nashed , W. El Hanafy , Sh. K. Ibraheem

We study the bounce cosmology to construct a singularity-free $f(\mathcal{R})$ model using the reconstruction technique. The formulation of the $f(\mathcal{R})$ model is based on the Raychaudhari equation, a key element employed in…

General Relativity and Quantum Cosmology · Physics 2024-07-30 Gaurav N. Gadbail , Simran Arora , P. K. Sahoo , Kazuharu Bamba

A regular bouncing universe is obtained in the context of a dilaton-gravity brane world scenario. The scale factor starts in a contracting inflationary phase both in the Einstein and in the string frame, it then undergoes a bounce (due to…

High Energy Physics - Theory · Physics 2009-11-10 Stefano Foffa

The question of geodesic completeness of cosmological spacetimes has recently received renewed scrutiny. A particularly interesting result is the observation that the well-known Borde-Guth-Vilenkin (BGV) theorem may misdiagnose geodesically…

General Relativity and Quantum Cosmology · Physics 2024-09-20 Sebastian Garcia-Saenz , Junjie Hua , Yunke Zhao

The main objective of this study is to investigate the phenomenon of the bouncing scenario of the universe. The most widely recognized cosmological framework is the standard cosmological model, sometimes referred to as the Big Bang model.…

General Relativity and Quantum Cosmology · Physics 2024-02-13 A. S. Agrawal

Recent data suggest that the Universe could be positively curved. Combined with an inflationary stage, this might lead to a curvature bounce instead of the Big Bang. The background evolution is presented, as a function of the parameters…

General Relativity and Quantum Cosmology · Physics 2021-01-20 Cyril Renevey , Aurélien Barrau , Killian Martineau , Selim Touati

We develop a non-singular bouncing cosmology using a non-trivial coupling of general relativity to fermionic fields. The usual Big Bang singularity is avoided thanks to a negative energy density contribution from the fermions. Our theory is…

General Relativity and Quantum Cosmology · Physics 2014-12-10 Stephon Alexander , Cosimo Bambi , Antonino Marciano , Leonardo Modesto

Friedmann-Lemaitre universes driven by a scalar field, spatially closed and bouncing, were recently studied by Martin and Peter in [1], with the conclusion that the spectrum of their large scale matter perturbations was generically modified…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nathalie Deruelle

We study the effective cosmological dynamics, emerging as the hydrodynamics of simple condensate states, of a group field theory model for quantum gravity coupled to a massless scalar field and reduced to its isotropic sector. The quantum…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Daniele Oriti , Lorenzo Sindoni , Edward Wilson-Ewing

The early universe need not be described by an incomplete inflationary phase connected to a separate, more exotic prehistory. Recent results show that, within non-static FRW cosmology, only positive spatial curvature permits a nonsingular,…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-01 Damien A. Easson

With a method in which the Friedmann equation is written in a form such that evolution of the scale factor can be treated as that of a particle in a "potential", we classify all possible cosmic evolutions in the DGP braneworld scenario with…

General Relativity and Quantum Cosmology · Physics 2012-10-12 Kaituo Zhang , Puxun Wu , Hongwei Yu

We investigate the cosmological consequences of a brane-world theory which incorporates time variations in the gravitational coupling G and the cosmological term Lambda. We analyze in detail the model where (dG/dt)/G ~ H and Lambda ~ H^2,…

General Relativity and Quantum Cosmology · Physics 2008-11-26 J. Ponce de Leon

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

We study flat Friedmann-Lemaitre-Robertson-Walker cosmological models for a scalar field coupled nonminimally to teleparallel gravity with generic coupling and potential functions. The goal of this paper is to determine the conditions under…

General Relativity and Quantum Cosmology · Physics 2016-08-08 Laur Jarv , Alexey Toporensky

We construct a class of viable bouncing models that are conformally related to cosmological inflation. There are three main difficulties in constructing such a model: (i) A stable (attractor) solution, (ii) A non-singular bounce, and (iii)…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-25 Debottam Nandi

It is notoriously difficult to construct a stable non-singular bouncing cosmology that avoids all possible instabilities throughout the entire evolution of the universe. In this work, we explore whether a non-singular bounce driven by a…

General Relativity and Quantum Cosmology · Physics 2025-02-26 Lara Bohnenblust , Serena Giardino , Lavinia Heisenberg , Nadine Nussbaumer

In the framework of massive gravity with a de Sitter reference metric, we study homogeneous and isotropic solutions with positive spatial curvature. Remarkably, we find that bounces can occur when cosmological matter satisfies the strong…

High Energy Physics - Theory · Physics 2015-06-16 David Langlois , Atsushi Naruko

An extremely fast exponential expansion of the Universe is typical for the stable version of the inflationary model, based on the anomaly-induced action of gravity. The total amount of exponential $e$-folds could be very large, before the…

High Energy Physics - Theory · Physics 2021-08-05 Wagno Cesar e Silva , Ilya L. Shapiro