English
Related papers

Related papers: New Isotropic and Anisotropic Sudden Singularities

200 papers

Spatially homogeneous but totally anisotropic and non-flat Bianchi type II cosmological model has been studied in general relativity in the presence of two minimally interacting fluids; a perfect fluid as the matter fluid and a hypothetical…

General Relativity and Quantum Cosmology · Physics 2012-06-18 Suresh Kumar , Ozgur Akarsu

In this work, we study the possibility of finite-time future cosmological singularities appearing in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. We present the theory in both the…

General Relativity and Quantum Cosmology · Physics 2022-05-10 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

We use expansion-normalised variables to investigate the Bianchi type VII$_0$ model with a tilted $\gamma$-law perfect fluid. We emphasize the late-time asymptotic dynamical behaviour of the models and determine their asymptotic states.…

General Relativity and Quantum Cosmology · Physics 2009-11-11 S. Hervik , R. J. van den Hoogen , W. C. Lim , A. A. Coley

We review our recent work on the classification of finite time singularities that arise in isotropic universes. This scheme is based on the exploitation of the Bel Robinson energy in a cosmological setting. We comment on the relation…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Ifigeneia Klaoudatou , Spiros Cotsakis

We consider the horizon problem in a homogeneous but anisotropic universe (Bianchi type I). We show that the problem cannot be solved if (1) the matter obeys the strong energy condition with the positive energy density and (2) the Einstein…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Takeshi Chiba , Shinji Mukohyama , Takashi Nakamura

We study the dynamics near finite-time singularities of flat isotropic universes filled with two interacting but otherwise arbitrary perfect fluids. The overall dynamical picture reveals a variety of asymptotic solutions valid locally…

General Relativity and Quantum Cosmology · Physics 2015-06-04 Spiros Cotsakis , Georgia Kittou

This article describes the theory of cosmological perturbations around a homogeneous and anisotropic universe of the Bianchi I type. Starting from a general parameterisation of the perturbed spacetime a la Bardeen, a complete set of gauge…

Astrophysics · Physics 2008-11-26 Thiago S. Pereira , Cyril Pitrou , Jean-Philippe Uzan

We present a general study of the dynamical properties of Anisotropic Bianchi Universes in the context of Einstein General Relativity. Integrability results using Kovalevskaya exponents are reported and connected to general knowledge about…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Jerome Perez

In our study, we explored the properties of a spatially homogeneous and anisotropic Bianchi type V I0 Universe. Our investigation centered on integrating cosmic domain walls into the f(R, T) theory of gravitation, initially proposed by…

General Relativity and Quantum Cosmology · Physics 2024-03-05 V. R. Patil , J. L. Pawde , R. V. Mapari , S. K. Waghmare

We study the future cosmological singularities in the framework of massive gravity and minimal massive bigravity theory. In this regards, we consider the possible classes of finite-time future singularities such as sudden, big rip, big…

General Relativity and Quantum Cosmology · Physics 2022-01-27 M. Mousavi , K. Atazadeh

We investigate the effects of quantum particle production on a classical sudden singularity occurring at fine time in a Friedmann universe. We use an exact solution to describe an initially radiation-dominated universe that evolves into a…

General Relativity and Quantum Cosmology · Physics 2012-07-06 John D. Barrow , Antonio B. Batista , Julio C. Fabris , M. J. S. Houndjo

Since the discovery of the accelerated expansion of the universe, it was necessary to introduce a new component of matter distribution called dark energy. The standard cosmological model considers isotropy of the pressure and assumes an…

General Relativity and Quantum Cosmology · Physics 2012-10-25 R. Chan , M. F. A. da Silva , J. F. Villas da Rocha

We show that globally and regularly hyperbolic future geodesically incomplete isotropic universes, except for the standard all-encompassing `big crunch', can accommodate singularities of only one kind, namely, those having a non-integrable…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Spiros Cotsakis , Ifigeneia Klaoudatou

Some analysis of the supernovae type Ia observational data seems to indicate that the Universe today is dominated by a phantom field, for which all energy conditions are violated. Such phantom field may imply a singularity in a future…

Astrophysics · Physics 2008-11-26 J. C. Fabris , S. V. B. Goncalves

We investigate a family of inhomogeneous and anisotropic gravitational fields exhibiting a future singularity at a finite value of the proper time. The studied spherically symmetric spacetimes are asymptotically Friedmann-Robertson-Walker…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Mauricio Cataldo , Paola Meza

Using squeezed vacuum state formalism of quantum optics, an approximate solution to the semiclassical Einstein equation is obtained in Bianchi type-I universe. The phenomena of nonclassical particle creation is also examined in the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 P. K. Suresh

The role of anisotropic components on the dark energy and the dynamics of the universe is investigated. An anisotropic dark energy fluid with different pressures along different spatial directions is assumed to incorporate the effect of…

General Physics · Physics 2018-04-16 B. Mishra , S. K. Tripathy , Pratik P Ray

This work explains how the presence of a Type-IV singularity (a mild singularity) can influence the dynamics of a bouncing universe. In particular, we examine bounce cosmology that appears with a Type-IV singularity in the context of a…

General Relativity and Quantum Cosmology · Physics 2022-05-24 Sergei D. Odintsov , Tanmoy Paul

We consider the dynamics of a Bianchi type I spacetime in the presence of dilaton and magnetic fields. The general solution of the Einstein-Maxwell dilaton field equations can be obtained in an exact parametric form. Depending on the…

General Relativity and Quantum Cosmology · Physics 2009-11-07 T. Harko , M. K. Mak

Anisotropic dark energy model with dynamic pressure anisotropies along different spatial directions is constructed at the backdrop of a spatially homogeneous diagonal Bianchi type $V$ $(BV)$ space-time in the framework of General…

General Physics · Physics 2017-05-10 B. Mishra , S. K. Tripathy
‹ Prev 1 3 4 5 6 7 10 Next ›