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Related papers: Emergent scenario in mimetic gravity

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This paper proposes a new avenue for understanding the cosmological singularity. The standard cosmological model contains a generic initial singularity usually referred to as the {\em big bang}. Herein, we present a novel idea to extend the…

General Relativity and Quantum Cosmology · Physics 2026-04-15 Justin C. Feng , Shinji Mukohyama , Jean-Philippe Uzan

By presenting a relation between average energy of the ensemble of probe photons and energy density of the Universe, in the context of {\it gravity's rainbow} or {\it doubly general relativity} scenario, we introduce a rainbow FRW Universe…

General Relativity and Quantum Cosmology · Physics 2015-12-15 M. Khodadi , Y. Heydarzade , K. Nozari , F. Darabi

We investigate stability of the Einstein static universe against the scalar, vector and tensor perturbations in the context of induced matter brane gravity. It is shown that in the framework of this model, the Einstein static universe has a…

General Relativity and Quantum Cosmology · Physics 2015-04-22 Y. Heydarzade , F. Darabi

We analyze the stability of the Einstein static universe by considering homogeneous scalar perturbations in the context of f(R) modified theories of gravity. By considering specific forms of f(R), the stability regions of the solutions are…

General Relativity and Quantum Cosmology · Physics 2012-06-22 Christian G. Boehmer , Lukas Hollenstein , Francisco S. N. Lobo

We present modified Gauss-Bonnet gravity without matter in four dimensions which accommodates flat emergent universe (EU) obtained in Einstein's general theory of gravity with a non-linear equation of state. The EU model is interesting…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-04 B. C. Paul , S. D. Maharaj , A. Beesham

The possibility of an emergent universe solution to Einstein's field equations allowing for an irreversible creation of matter at the expense of the gravitational field is shown. With the universe being chosen as spatially flat FRW…

General Relativity and Quantum Cosmology · Physics 2016-09-27 Sunandan Gangopadhyay , Anirban Saha , S. Mukherjee

In this work we propose an alternative scheme for an Emergent Universe scenario where the universe is initially in a static state supported by a scalar field located in a false vacuum. The universe begins to evolve when, by quantum…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Pedro Labrana

In the context of Einstein gravity, if the null energy condition (NEC) is satisfied, the energy density in expanding space-times always decreases while in contracting space-times the energy density grows and the universe eventually…

General Relativity and Quantum Cosmology · Physics 2016-07-04 Anna Ijjas , Justin Ripley , Paul J. Steinhardt

Observations indicate that the universe is effectively flat, but they do not rule out a closed universe. The role of positive curvature is negligible at late times, but can be crucial in the early universe. In particular, positive curvature…

General Relativity and Quantum Cosmology · Physics 2010-04-06 George Ellis , Roy Maartens

The emergent universe scenario provides a possible alternative to bouncing cosmology to avoid the Big Bang singularity problem. In this paper we study the realization of the emergent universe scenario by making use of Quintom matter with an…

High Energy Physics - Theory · Physics 2012-11-21 Yi-Fu Cai , Mingzhe Li , Xinmin Zhang

Starting from the assumption that general relativity might be an emergent phenomenon showing up at low-energies from an underlying microscopic structure, we re-analyze the stability of a static closed Universe filled with radiation. In this…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Carlos Barcelo , Grigory Volovik

General non-singular accelerating cosmological solutions for an initial cosmic period of pure vacuum birth era are derived. This vacuum era is described by a varying cosmological "constant" suggested by the Renormalisation Group flow of…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Georgios Kofinas , Vasilios Zarikas

Hybrid metric-Palatini gravity is a recent and novel approach to modified theories of gravity, which consists of adding to the metric Einstein-Hilbert Lagrangian an f(R) term constructed a la Palatini. It was shown that the theory passes…

General Relativity and Quantum Cosmology · Physics 2015-02-19 Christian G. Boehmer , Francisco S. N. Lobo , Nicola Tamanini

Oscillating solutions to the effective equations of Loop Quantum Cosmology have been suggested for the role of an `eternal seed', providing a possible starting point for the emergent universe scenario. We investigate the stability of a…

High Energy Physics - Theory · Physics 2015-06-19 Audrey T. Mithani , Alexander Vilenkin

We study the static cosmological solutions and their stability at background level in the framework of massive bigravity theory with Friedmann-Robertson-Walker (FRW) metrics. By the modification proposed in the cosmological equations…

General Relativity and Quantum Cosmology · Physics 2017-05-17 M. Mousavi , F. Darabi

One of the greatest problems of standard cosmology is the Big Bang singularity. Previously it has been shown that non-local ghostfree higher-derivative modifications of Einstein gravity in the ultra-violet regime can admit non-singular…

High Energy Physics - Theory · Physics 2010-12-03 Tirthabir Biswas , Tomi Koivisto , Anupam Mazumdar

We consider a non-singular origin for the Universe starting from an Einstein static Universe, the so called "emergent universe" scenario, in the framework of a theory which uses two volume elements $\sqrt{-{g}}d^{4}x$ and $\Phi d^{4}x$,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Eduardo Guendelman , Pedro Labrana

In the present work we consider the existence and stability of Einstein static {\sf ES} Universe in Brans-Dicke ({\sf BD}) theory with non-vanishing spacetime torsion. In this theory, torsion field can be generated by the {\sf BD} scalar…

General Physics · Physics 2019-03-26 Hamid Shabani , Amir Hadi Ziaie

It has been recently pointed out by Mithani-Vilenkin that certain emergent universe scenarios which are classically stable are nevertheless unstable semiclassically to collapse. Here, we show that there is a class of emergent universes…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Sergio del Campo , Eduardo I. Guendelman , Ramon Herrera , Pedro Labrana

In this work, we study the issue of the past and future cosmological singularities in the context of the fourth-order conformal Weyl gravity. In particular, we investigate the emergent universe scenario proposed by Ellis {\it et al}, and…

General Relativity and Quantum Cosmology · Physics 2020-06-02 Yaghoub Heydarzade