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In this paper we perform a systematic study of spatially flat $[(3+D)+1]$-dimensional Einstein-Gauss-Bonnet cosmological models with $\Lambda$-term. We consider models that topologically are the product of two flat isotropic subspaces with…

High Energy Physics - Theory · Physics 2017-08-21 Sergey A. Pavluchenko

We provide the correspondence between the variables in the Jordan frame and those in the Einstein frame in scalar-tensor gravity and consider the frame-(in)dependence of the cosmological observables. In particular, we show that the…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Takeshi Chiba , Masahide Yamaguchi

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

In the mathematically rigorous analysis of semiclassical Einstein's equations, the renormalisation of the stress-energy tensor plays a crucial role. We address such a topic in the case of a scalar field with both arbitrary mass and coupling…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Claudio Dappiaggi , Klaus Fredenhagen , Nicola Pinamonti

The methods of dynamical systems have found wide applications in cosmology, with focus either upon inflation or upon the passage into dark energy era. In this paper, we endeavor to capture the whole history of the universe into a dynamical…

General Relativity and Quantum Cosmology · Physics 2020-07-15 Jibitesh Dutta , Laur Jarv , Wompherdeiki Khyllep , Sulev Tokke

We present a Mathematica package for performing algebraic and numerical computations in cosmological models based on supersymmetric theories. The programs allow for (I) evaluation and study of the properties of a scalar potential in a large…

High Energy Physics - Theory · Physics 2007-05-23 Renata Kallosh , Sergey Prokushkin

This paper is the first part of a trilogy dedicated to the following problem: given spherically symmetric characteristic initial data for the Einstein-Maxwell-scalar field system with a cosmological constant $\Lambda$, with the data on the…

General Relativity and Quantum Cosmology · Physics 2015-06-22 João L. Costa , Pedro M. Girão , José Natário , Jorge Drumond Silva

In the framework of teleparallel gravity, the Friedman-Robertson-Walker cosmological model with scalar tensor theory where scalar field is non-minimally coupled to both the torsion scalar and boundary term is studied. Utilizing the Noether…

General Relativity and Quantum Cosmology · Physics 2018-08-29 Ganim Gecim , Yusuf Kucukakca

We study the classical and quantum models of a flat Friedmann-Robertson-Walker (FRW) space-time, coupled to a perfect fluid, in the context of the consensus and a gauge-fixed Lagrangian frameworks. It is shown that, either in the usual or…

General Relativity and Quantum Cosmology · Physics 2015-03-19 Babak Vakili

We study integrable models in the Bianchi I metric case with scalar fields minimally and non-minimally coupled with gravity and the correspondence between their general solutions. Using the model with a minimally coupled scalar field and a…

General Relativity and Quantum Cosmology · Physics 2018-01-26 A. Yu. Kamenshchik , E. O. Pozdeeva , A. Tronconi , G. Venturi , S. Yu. Vernov

We present the solution space for the case of a minimally coupled scalar field with arbitrary potential in a FLRW metric. This is made possible due to the existence of a nonlocal integral of motion corresponding to the conformal Killing…

General Relativity and Quantum Cosmology · Physics 2016-06-22 N. Dimakis , A. Karagiorgos , Adamantia Zampeli , Andronikos Paliathanasis , T. Christodoulakis , Petros A. Terzis

We report a method of solving for canonical scalar field exact solution in a non-flat FLRW universe with barotropic fluid using non-linear Schr\"{o}dinger (NLS)-type formulation in comparison to the method in the standard Friedmann…

General Relativity and Quantum Cosmology · Physics 2009-02-18 Burin Gumjudpai

The paper deals with cosmological solutions describing different phases of the Universe for the homogeneous and isotropic FLRW model of the Universe with torsion. Normally, torsion field is not suitable for maximally symmetric space time…

General Relativity and Quantum Cosmology · Physics 2020-10-30 Akash Bose , Subenoy Chakraborty

In this study, FRW-cosmologies with some matter groups such as monopole-domain wall, monopole-Chaplygin gas and monopole-strange quark matter in the scalar theory of gravitation based on Lyra geometry are investigated. We expand two exact…

General Relativity and Quantum Cosmology · Physics 2012-09-28 Melis Ulu Dogru , Derya Baykal

We construct a compact phase space for flat FLRW spacetimes with standard matter described by a perfect fluid with a barotropic equation of state for general f(R) theories of gravity, subject to certain conditions on the function f. We then…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Mohamed Abdelwahab , Rituparno Goswami , Peter K. S. Dunsby

We generalize the scalar tensor bigravity models to the non-minimal kinetic coupling scalar tensor bigravity models with two scalar fields whose kinetic terms are non-minimally coupled to two Einstein tensors constructed by two metrics. We…

General Relativity and Quantum Cosmology · Physics 2015-08-06 F. Darabi , M. Mousavi

This work studies the quantum cosmology of a closed, spatially homogeneous, and isotropic FLRW minisuperspace model with electromagnetic radiation as a matter content. We solve the associated Wheeler-DeWitt (WDW) equation using the…

General Relativity and Quantum Cosmology · Physics 2023-04-20 S. Jalalzadeh , A. Mohammadi , D. Demir

In recent years, the use of conformal transformation techniques has become widespread in the literature on gravitational theories alternative to general relativity, on cosmology, and on nonminimally coupled scalar fields. Typically, the…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Valerio Faraoni , Edgard Gunzig , Pasquale Nardone

In the context of scalar-tensor models of dark energy and inflation, the dynamics of vacuum scalar-tensor cosmology are analysed without specifying the coupling function or the scalar field potential. A conformal transformation to the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 V. Faraoni , M. N. Jensen , S. A. Theuerkauf

The Universe is homogeneous and isotropic on large scales, so on those scales it is usually modelled as a Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) space-time. The non-linearity of the Einstein field equations raises concern over…

General Relativity and Quantum Cosmology · Physics 2021-03-03 Yonadav Barry Ginat