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Related papers: Future singularity in an anisotropic universe

200 papers

We investigate the cosmological behavior in a universe governed by time asymmetric extensions of general relativity, which is a novel modified gravity based on the addition of new, time-asymmetric, terms on the Hamiltonian framework, in a…

General Relativity and Quantum Cosmology · Physics 2015-11-11 Genly Leon , Emmanuel N. Saridakis

We consider here the genericity aspects of spacetime singularities that occur in cosmology and in gravitational collapse. The singularity theorems (that predict the occurrence of singularities in general relativity) allow the singularities…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Pankaj S. Joshi

Cardassian models are an alternative to general relativity which have been proposed as an approach to explaining accelerated cosmic expansion while avoiding directly introducing dark energy. They are generally formulated only in the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Nikolaus Berndt , Alan D. Rendall

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

A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, generates an anisotropization of the large-scale geometry of the Universe,…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-28 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

We discuss various types of exotic (non-standard) singularities in the Universe: a Big-Rip (BR or type I), a Sudden Future Singularity (SFS or type II), a Generalized Sudden Future Singularity, a Finite Scale Factor singularity (FSF or type…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Mariusz P. Dabrowski , Tomasz Denkiewicz

In this talk we would like to analyse the appearance of singularities in FLRW cosmological models which evolve close to w=-1, where w is the barotropic index of the universe. We relate small terms in cosmological time around w=-1 with the…

General Relativity and Quantum Cosmology · Physics 2015-06-23 L. Fernández-Jambrina

We consider a cosmological model in which the two major fluid components of the Universe, dark energy and dark matter, flow with distinct four-velocities. This cosmological configuration is equivalent to a single anisotropic fluid,…

General Relativity and Quantum Cosmology · Physics 2013-07-24 Tiberiu Harko , Francisco S. N. Lobo

Understanding the late-time acceleration of the universe and its subtleties is one of the biggest mysteries in cosmology. A lot of different approaches have been put forward to deal with this, ranging from the conventional cosmological…

General Relativity and Quantum Cosmology · Physics 2024-09-30 Oem Trivedi , Maxim Khlopov

Anisotropic cosmological models are constructed in $f(R,T)$ gravity theory to investigate the dynamics of universe concerning the late time cosmic acceleration. Using a more general and simple approach, the effect of the coupling constant…

General Physics · Physics 2018-10-05 B. Mishra , Sankarsan Tarai , S. K. Tripathy

We review finite-time future singularities in modified gravity. We reconstruct an explicit model of modified gravity realizing a crossing of the phantom divide and show that the Big Rip singularity appears in the modified gravitational…

High Energy Physics - Theory · Physics 2009-06-23 Kazuharu Bamba

Closed, singularity-free, inflationary cosmological models have recently been studied in the context of general relativity. Despite their appeal, these so called emergent models suffer from a number of limitations. These include the fact…

Astrophysics · Physics 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

We show that a singularity can occur at a finite future time in an expanding Friedmann universe even when the density is positive and the density plus the sum of the principal pressures is positive. Explicit examples are constructed and a…

General Relativity and Quantum Cosmology · Physics 2009-11-10 John D. Barrow

The occurrence of singularities where spacetime curvature becomes infinite and geodesic evolution breaks down are inevitable events in classical general relativity (GR) unless one chooses an exotic matter violating weak energy condition.…

General Relativity and Quantum Cosmology · Physics 2024-11-05 Bao-Fei Li , Parampreet Singh

Loop quantum cosmology applies techniques derived for a background independent quantization of general relativity to cosmological situations and draws conclusions for the very early universe. Direct implications for the singularity problem…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald

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

In cosmology based on general relativity, the universe is modeled as a fluid. The transition from the Einstein field equation to its large-scale (cosmological) version is thus analogous to the transition, for a system consisting of a large…

General Physics · Physics 2018-10-18 Gregory Ryskin

We construct a piecewise model that gives a physical viable realization of finite-time future singularity for a spatially flat Friedmann-Robertson-Walker universe within the interacting dark matter--dark energy framework, with the latter…

General Relativity and Quantum Cosmology · Physics 2017-03-14 Mauricio Cataldo , Luis P. Chimento , Martín G. Richarte

We demonstrate that finite time singularities of Type IV can be consistently incorporated in the Universe's cosmological evolution, either appearing in the inflationary era, or in the late-time regime. While using only one scalar field…

General Relativity and Quantum Cosmology · Physics 2015-12-02 Shin'ichi Nojiri , S. D. Odintsov , V. K. Oikonomou , Emmanuel N. Saridakis

We study future singularity in teleparallel dark energy models, particularly its behavior and its (non)occurrence in the observationally viable models. For the models with a general self-potential of the scalar field, we point out that both…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-24 Chao-Qiang Geng , Je-An Gu , Chung-Chi Lee