English
Related papers

Related papers: Emergent Universe from Energy-Momentum Squared Gra…

200 papers

Scale-independent EMSG is a particular model of energy-momentum squared gravity (EMSG) in which the new terms in the Einstein field equations arising from the EMSG theory enter with the same power as the usual terms from Einstein-Hilbert…

General Relativity and Quantum Cosmology · Physics 2023-02-24 Ozgur Akarsu , N. Merve Uzun

The BFSS matrix model is a suggested non-perturbative definition of string theory. Starting from a thermal state of this matrix model, we show how space and time can emerge dynamically. Results from the IKKT matrix model indicate that the…

High Energy Physics - Theory · Physics 2022-12-07 Suddhasattwa Brahma , Robert Brandenberger , Samuel Laliberte

In this paper, in the framework of massive bigravity, we study all possible cosmic evolutions by using a method in which the modified Friedmann equation is written in a form where the scale factor evolves like the motion of a particle under…

General Relativity and Quantum Cosmology · Physics 2019-05-16 M. Mousavi , F. Darabi

A cosmological scenario where dark matter interacts with a variable vacuum energy for a spatially flat Friedmann-Robertson-Walker space-time is proposed and analysed to show that with a linear equation of state and a particular interaction…

General Relativity and Quantum Cosmology · Physics 2017-09-11 Emiliano Marachlian , Iván E. Sánchez G. , Osvaldo P. Santillán

A new class of gravity-matter models defined in terms of two independent non-Riemannian volume forms (alternative generally covariant integration measure densities) on the space-time manifold are studied in some detail. These models involve…

General Relativity and Quantum Cosmology · Physics 2015-06-22 Eduardo Guendelman , Ramón Herrera , Pedro Labraña , Emil Nissimov , Svetlana Pacheva

Emergent scenario of cosmic evolution is a topic of great interest in recent cosmology, especially because it describes a non-singular origin of the Universe unlike the Big-Bang models. This types of cosmic evolution pattern have already…

General Relativity and Quantum Cosmology · Physics 2023-09-01 Subhayan Maity , Sujayita Bakra

We emphasize that noncommutative (NC) spacetime necessarily implies emergent spacetime if spacetime at microscopic scales should be viewed as NC. In order to understand NC spacetime correctly, we need to deactivate the thought patterns that…

High Energy Physics - Theory · Physics 2016-10-10 Hyun Seok Yang

Emergent modified gravity presents a new set of generally covariant gravitational theories in which the space-time metric is not directly given by one of the fundamental fields. A metric compatible with the modified dynamics of gravity is…

General Relativity and Quantum Cosmology · Physics 2024-04-09 Martin Bojowald , Erick I. Duque

We find a class of solutions for a homogeneous and isotropic universe in which the initially expanding universe stops expanding, experiences contraction, and then expands again (the "bounce"), in the framework of Einstein gravity with a…

General Relativity and Quantum Cosmology · Physics 2019-06-26 Hiroki Matsui , Fuminobu Takahashi , Takahiro Terada

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 obtain cosmological solutions which admit emergent universe (EU) scenario in the framework of Einstein Gauss-Bonnet gravity coupled with a dilaton field in four dimensions. The coupling parameter of the Gauss-Bonnet terms and the dilaton…

High Energy Physics - Theory · Physics 2015-05-13 B C Paul , S Ghose

Massive gravity is a modified theory of general relativity. In this paper, we study, using a method in which the scale factor changes as a particle in a "potential", all possible cosmic evolutions in a ghost-free massive gravity. We find…

General Relativity and Quantum Cosmology · Physics 2013-03-21 Kaituo Zhang , Puxun Wu , Hongwei Yu

We provide an Emergent Universe picture in which the fine-tuning on the initial conditions is replaced by cut-off physics, implemented on a semiclassical level when referred to the Universe dynamics and on a purely quantum level for the…

General Relativity and Quantum Cosmology · Physics 2023-09-11 Gabriele Barca , Giovanni Montani , Alessandro Melchiorri

We address issues on the origin of gravity and the cosmological constant problem based on a recent understanding about the correspondence between noncommutative field theory and gravity. We suggest that the cosmological constant problem can…

High Energy Physics - Theory · Physics 2008-03-28 Hyun Seok Yang

In this paper, we have assumed a flat Friedmann-Lemaitr\'e-Robertson-Walker universe endowed with a general form of dissipation. The source of dissipation is considered to be a bulk viscous pressure $\Pi$ which leads to an adiabatic…

General Relativity and Quantum Cosmology · Physics 2026-03-10 Subhajit Saha

The exactly solvable quantum model of the homogeneous, isotropic and closed universe in the matter-energy production epoch is considered. It is assumed that the universe is originally filled with a uniform scalar field and a perfect fluid…

General Relativity and Quantum Cosmology · Physics 2011-07-19 V. E. Kuzmichev , V. V. Kuzmichev

An oscillating universe cycles through a series of expansions and contractions. We propose a model in which ``phantom'' energy with $p < -\rho$ grows rapidly and dominates the late-time expanding phase. The universe's energy density is so…

Astrophysics · Physics 2014-10-13 Matthew G. Brown , Katherine Freese , William H. Kinney

We analyze the stability of the Einstein static universe in scalar-tensor theory of gravity, and find it can be stable against both scalar and tensor perturbations under certain conditions. By assuming the emergent scenario originating from…

General Relativity and Quantum Cosmology · Physics 2023-06-13 Qihong Huang , He Huang , Bing Xu

The dilaton-gravity sector of a linear in the scalar curvature, scale invariant Two Measures Field Theory (TMT), is explored in detail in the context of closed FRW cosmology and shown to allow stable emerging universe solutions. The model…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Sergio del Campo , Eduardo I. Guendelman , Alexander B. Kaganovich , Ramon Herrera , Pedro Labrana

We show that in the isentropic scenario the first order thermodynamical particle creation model gives an emergent universe solution even when the chemical potential is non-zero. However there exists no emergent universe scenario in the…

General Relativity and Quantum Cosmology · Physics 2017-05-01 Saumya Ghosh , Sunandan Gangopadhyay