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We consider the Szekeres universe with an inhomogeneous dust fluid and a homogeneous and isotropic ghost matter source with equation of state $p_{g}=\left( \gamma-1\right) \rho_{g},$ where $\gamma$ is a constant. The field equations…

General Relativity and Quantum Cosmology · Physics 2020-01-17 John D. Barrow , Andronikos Paliathanasis

We consider the existence of an "inflaton" described by an homogeneous scalar field in the Szekeres cosmological metric. The gravitational field equations are reduced to two families of solutions which describe the homogeneous…

General Relativity and Quantum Cosmology · Physics 2018-10-17 John D. Barrow , Andronikos Paliathanasis

We investigate the existence of inhomogeneous Szekeres spacetimes in Einstein-\ae ther theory. We show that inhomogeneous solutions which can be seen as extension of the Szekeres solutions existing in Einstein-\ae ther gravity only for a…

General Relativity and Quantum Cosmology · Physics 2020-06-17 Andronikos Paliathanasis

It is shown that inhomogeneous Szekeres and Stephani universes exist corresponding to non-dissipative binary mixtures of perfect fluids in local thermal equilibrium. This result contradicts a recent statement by Z\'arate and Quevedo (2004…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Bartolomé Coll , Joan Josep Ferrando

In this paper we present a class of exact inhomogeneous solutions to Einstein's equations for higher dimensional Szekeres metric with perfect fluid and a cosmological constant. We also show particular solutions depending on the choices of…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Subenoy Chakraborty , Ujjal Debnath

We show that small homogeneous solutions to the Einstein-Boltzmann-scalar field system exist globally towards the future and tend to the de Sitter solution in a suitable sense. More specifically, we assume that the spacetime is of Bianchi…

General Relativity and Quantum Cosmology · Physics 2024-06-18 Ho Lee , Jiho Lee , Ernesto Nungesser

The exact Friedman solution to the field equations of General Relativity (GR) describing a homogeneous and isotropic universe together with its linear and higher-order perturbations are the theoretical roots of the current standard model of…

General Relativity and Quantum Cosmology · Physics 2024-12-20 Marie-Noëlle Célérier

This paper presents the cosmological applications of the quasispherical Szekeres model. The quasispherical Szekeres model is an exact solution of the Einstein field equations, which represents a time-dependent mass dipole superposed on a…

Astrophysics · Physics 2007-05-23 Krzysztof Bolejko

We review spherical and inhomogeneous analytic solutions of the field equations of Einstein and of scalar-tensor gravity, including Brans-Dicke theory, non-minimally (possibly conformally) coupled scalar fields, Horndeski, and beyond…

General Relativity and Quantum Cosmology · Physics 2021-07-28 Valerio Faraoni , Andrea Giusti , Bardia H. Fahim

A new family of spherically symmetric inhomogeneous solutions of Brans-Dicke gravity is generated using the Fonarev solution of general relativity as a seed and a map from the Einstein to the Jordan conformal frame. The Brans-Dicke scalar…

General Relativity and Quantum Cosmology · Physics 2017-09-06 Valerio Faraoni , Shawn D. Belknap-Keet

We use the Szekeres inhomogeneous relativistic models in order to fit supernova combined data sets. We show that with a choice of the spatial curvature function that is guided by current observations, the models fit the supernova data…

Two families of exact simple solutions of Einstein field equations for inhomogeneous stiff cosmologies are presented. The method to obtain the solutions is based on the introduction of auxiliary functions in order to cast the Einstein…

Astrophysics · Physics 2009-06-23 Guillermo A. Gonzalez , Fabio D. Lora , Jenrry A. Jaimes

We report a new one-parameter family of spherically symmetric, inhomogeneous, and time-dependent solutions of the vacuum Brans-Dicke field equations which are conformal to the Roberts scalar field geometries of Einstein gravity. The new…

General Relativity and Quantum Cosmology · Physics 2021-04-12 Bardia H. Fahim , Valerio Faraoni , Andrea Giusti

The generalized Szekeres family of solution for quasi-spherical space-time of higher dimensions are obtained in the scalar tensor theory of gravitation. Brans-Dicke field equations expressed in Dicke's revised units are exhaustively solved…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Asit Banerjee , Ujjal Debnath , Subenoy Chakraborty

We examine a novel class of toy models of cosmological inhomogeneities by smoothly matching along a suitable hypersurface an arbitrary number of sections of "quasi flat" inhomogeous and anisotropic Szekeres-II models to sections of any…

General Relativity and Quantum Cosmology · Physics 2021-04-14 Sebastián Nájera , Roberto A. Sussman

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.…

General Physics · Physics 2012-11-15 Anirudh Pradhan , Ajay Kumar Singh , H. Amirhashchi

We obtain an elegant and useful description of the dynamics of Szekeres dust models (in their full generality) by means of `quasi-local' scalar variables constructed by suitable integral distributions that can be interpreted as weighed…

General Relativity and Quantum Cosmology · Physics 2015-05-30 Roberto A. Sussman , Krzysztof Bolejko

A new class of solutions of Einstein field equations has been investigated for inhomogeneous cylindrically symmetric space-time with string source. To get the deterministic solution, it has been assumed that the expansion ($\theta$) in the…

General Relativity and Quantum Cosmology · Physics 2014-05-06 Anirudh Pradhan , A. K. Yadav , R. P. Singh , V. K. Singh

We examine the relation between the Szekeres models and relativistic Lagrangian perturbation schemes, in particular the Relativistic Zel'dovich Approximation (RZA). We show that the second class of the Szekeres solutions is exactly…

General Relativity and Quantum Cosmology · Physics 2021-01-07 Ismael Delgado Gaspar , Thomas Buchert

A new Lagrangian framework has recently been proposed to describe interactions between relativistic perfect fluids and scalar fields. In this paper we investigate the Einstein static universe in this new class of theories, which have been…

General Relativity and Quantum Cosmology · Physics 2016-01-06 Christian G. Boehmer , Nicola Tamanini , Matthew Wright
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