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Related papers: Future singularity in an anisotropic universe

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We discuss recent developments related to certain blow up methods suitable for the analysis of cosmological singularities and asymptotics. We review results obtained in a variety of currently popular themes and describe ongoing research…

General Relativity and Quantum Cosmology · Physics 2013-10-11 Spiros Cotsakis

We study the effects of inhomogeneities on the evolution of the Universe, by considering a range of cosmological models with discretized matter content. This is done using exact and fully relativistic methods that exploit the symmetries in…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Timothy Clifton , Daniele Gregoris , Kjell Rosquist , Reza Tavakol

We present a class of graviton-dilaton models in which a homogeneous isotropic universe, such as our observed one, evolves with no singularity at any time. Such models may stand on their own as interesting models for singularity free…

High Energy Physics - Theory · Physics 2009-10-30 S. Kalyana Rama

Isotropic cosmological singularities are singularities which can be removed by rescaling the metric. In some cases already studied (gr-qc/9903008, gr-qc/9903009, gr-qc/9903018) existence and uniqueness of cosmological models with data at…

General Relativity and Quantum Cosmology · Physics 2017-08-23 K. P. Tod

We investigate various dark energy models by taking into account the thermal effects induced from Hawking radiation on the apparent horizon of the Universe, for example near a finite-time future singularity. If the dark energy density…

General Relativity and Quantum Cosmology · Physics 2021-02-17 Artyom V. Astashenok , Sergei D. Odintsov , Vasilis K. Oikonomou

Cosmological observations allow the possibility that dark energy is caused by phantom fields. These fields typically lead to the occurrence of singularities in the late Universe. We review here the status of phantom singularities and their…

General Relativity and Quantum Cosmology · Physics 2019-10-22 Mariam Bouhmadi-López , Claus Kiefer , Prado Martín-Moruno

We discuss whether the future extrapolation of the present cosmological state may lead to a singularity even in case of "conventional" (negative) pressure of the dark energy field, namely $w=p/\rho \geq -1$. The discussion is based on an…

General Relativity and Quantum Cosmology · Physics 2009-11-10 M. Gasperini

Loop quantum cosmology is an application of recent developments for a non-perturbative and background independent quantization of gravity to a cosmological setting. Characteristic properties of the quantization such as discreteness of…

Astrophysics · Physics 2009-11-13 Martin Bojowald

In this work, Emergent Universe scenario has been developed in general homogeneous anisotropic model and for the inhomogeneus LTB model. In the first case, it is assumed that the matter in the universe has two components - one is perfect…

General Relativity and Quantum Cosmology · Physics 2011-11-10 Sudeshna Mukerji , Nairwita Mazumder , Ritabrata Biswas , Subenoy Chakraborty

We study the singularity created in the supercritical collapse of a spherical massless scalar field. We first model the geometry and the scalar field to be homogeneous, and find a generic solution (in terms of a formal series expansion)…

General Relativity and Quantum Cosmology · Physics 2010-11-19 Lior M. Burko

We consider ideal fluid and equivalent scalar field dark energy universes where all four known types of finite-time, future singularities occur at some parameter values. It is demonstrated that pressure/energy density of such…

High Energy Physics - Theory · Physics 2015-05-13 Shin'ichi Nojiri , Sergei D. Odintsov

We look at some dynamic geometries produced by scalar fields with both the "right" and the "wrong" sign of the kinetic energy. We start with anisotropic homogeneous universes with closed, open and flat spatial sections. A non-singular…

High Energy Physics - Theory · Physics 2009-11-10 Alexander Feinstein , Sanjay Jhingan

The long story of the oscillatory approach to the initial cosmological singularity and its more recent incarnation in multidimensional universe models is told.

General Relativity and Quantum Cosmology · Physics 2014-09-18 Vladimir A. Belinski

We consider the problem of the nature and possible types of spacetime singularities that can form during the evolution of \emph{FRW} universes in general relativity. We show that by using, in addition to the Hubble expansion rate and the…

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

The future finite-time singularities emerging in alternative gravity dark energy models are classified and studied in Jordan and Einstein frames. It is shown that such singularity may occur even in flat spacetime for the specific choice of…

High Energy Physics - Theory · Physics 2009-06-30 S. Capozziello , M. De Laurentis , S. Nojiri , S. D. Odintsov

We assume the anisotropic model of the Universe in the framework of varying speed of light $c$ and varying gravitational constant $G$ theories and study different types of singularities. For the singularity models, we write the scale…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Ujjal Debnath , Soumak Nag

We demonstrate the existence of sudden, finite-time, singularities, with constant scale factor, expansion rate and density, in expanding Bianchi type IX universes with free anisotropic pressures. A new type of non-simultaneous anisotropic…

General Relativity and Quantum Cosmology · Physics 2020-07-29 John D. Barrow

We consider possible resolutions of singularities in a contracting anisotropic universe for a class of higher derivative gravity theories. We give evidence that for our models the big crunch singularity may be replaced by a nearly flat…

High Energy Physics - Theory · Physics 2008-11-26 Philipp Höffer v. Loewenfeld , Ivo Sachs

This paper proposes a new avenue for understanding the cosmological singularity. The standard cosmological model contains a generic initial singularity usually referred to as the {\em big bang}. Herein, we present a novel idea to extend the…

General Relativity and Quantum Cosmology · Physics 2026-04-15 Justin C. Feng , Shinji Mukohyama , Jean-Philippe Uzan

We review the general features of nonsingular universes ({\em i.e.} those that go from an era of accelerated collapse to an expanding era without displaying a singularity) as well as cyclic universes. We discuss the mechanisms behind the…

Astrophysics · Physics 2008-12-18 M. Novello , S. E. Perez Bergliaffa