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Related papers: Dynamical Systems in Cosmology: Reviewing An Alter…

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We extend the investigation of cosmological dynamics of the general non-canonical scalar field models by dynamical system techniques for a broad class of potentials and coupling functions. In other words, we do not restrict the analysis to…

General Relativity and Quantum Cosmology · Physics 2019-04-30 Jibitesh Dutta , Wompherdeiki Khyllep , Hmar Zonunmawia

This review on dark energy is intended for a wider audience, beginners as well as experts. It contains important notes on various aspects of dark energy and its alternatives. The section on Newtonian cosmology followed by heuristic…

High Energy Physics - Theory · Physics 2009-09-26 M. Sami

For general number of spatial dimensions we investigate the cosmological dynamics driven by a cosmological constant and by a source with barotropic equation of state. It is assumed that for both those sources the energy density can be…

General Relativity and Quantum Cosmology · Physics 2022-11-09 A. A. Saharian , R. M. Avagyan , E. R. Bezerra de Mello , V. Kh. Kotanjyan , T. A. Petrosyan , H. G. Babujyan

Cosmological models can be studied effectively using dynamical systems techniques. Starting from Brown's formulation of the variational principle for relativistic fluids, we introduce new types of couplings involving a perfect fluid, a…

General Relativity and Quantum Cosmology · Physics 2024-09-13 Christian G. Boehmer , Antonio d'Alfonso del Sordo

The cosmographic technique is a powerful model-independent tool for distinguishing between competing cosmological scenarios. The key strengths and weaknesses of standard cosmography are discussed in view of healing the convergence problem…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-01 Salvatore Capozziello , Rocco D'Agostino

Methods of dynamical systems have been used to study homogeneous and isotropic cosmological models with a varying speed of light (VSL). We propose two methods of reduction of dynamics to the form of planar Hamiltonian dynamical systems for…

General Relativity and Quantum Cosmology · Physics 2008-07-22 Marek Szydlowski , Adam Krawiec

There is now strong evidence that the current energy density of the Universe is dominated by dark energy with an equation of state w<-1/3, which is causing accelerated expansion. The build-up of structure within such Universes is subject to…

Astrophysics · Physics 2008-11-26 Will J. Percival

We investigate the cosmological dynamics of the recently proposed extended chameleon models at both background and linear perturbation levels. Dynamical systems techniques are employed to fully characterize the evolution of the universe at…

General Relativity and Quantum Cosmology · Physics 2017-03-09 Nicola Tamanini , Matthew Wright

We discuss a mechanism that induces a time-dependent vacuum energy on cosmological scales. It is based on the instability induced renormalization triggered by the low energy quantum fluctuations in a Universe with a positive cosmological…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Alfio Bonanno , Sante Carloni

In this book are studied, from the perspective of the dynamical systems, several Universe models. In chapter 1 we give a bird's eye view on cosmology and cosmological problems. Chapter 2 is devoted to a brief review on some results and…

General Relativity and Quantum Cosmology · Physics 2014-12-19 Genly Leon , Carlos R. Fadragas

We expand the dynamical systems investigation of cosmological scalar fields characterised by kinetic corrections presented in [N. Tamanini, Phys. Rev. D 89 (2014) 083521]. In particular we do not restrict the analysis to exponential…

General Relativity and Quantum Cosmology · Physics 2017-03-09 Jibitesh Dutta , Wompherdeiki Khyllep , Nicola Tamanini

We propose to use dynamical symmetries of the field equations, in order to classify the dark energy models in the context of scalar field (quintessence or phantom) FLRW cosmologies. Practically, symmetries provide a useful mathematical tool…

General Relativity and Quantum Cosmology · Physics 2014-11-21 Andronikos Paliathanasis , Michael Tsamparlis , Spyros Basilakos

A wide range of large scale observations hint towards possible modifications on the standard cosmological model which is based on a homogeneous and isotropic universe with a small cosmological constant and matter. These observations, also…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-21 Leandros Perivolaropoulos

We analyse dark energy models where self-interacting three-forms or phantom fields drive the accelerated expansion of the Universe. The dynamics of such models is often studied by rewriting the cosmological field equations in the form of a…

General Relativity and Quantum Cosmology · Physics 2012-12-11 Christian G. Boehmer , Nyein Chan , Ruth Lazkoz

We propose and investigate a class of dynamical dark energy models in which the cosmological constant evolves from negative values in the early Universe to a positive value at low redshifts. This framework includes a generalised ladder-step…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-20 Mariam Bouhmadi-López , Beñat Ibarra-Uriondo

A cosmological constant, Lambda, is the most natural candidate to explain the origin of the dark energy (DE) component in the Universe. However, due to experimental evidence that the equation of state (EOS) of the DE could be evolving with…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Joan Sola , Hrvoje Stefancic

The work deals with homogeneous and isotropic, flat FRW model of the universe which is filled up with non-interacting dark matter and dark energy to compatible with recent observational evidences. By choosing the dark energy in the form of…

General Relativity and Quantum Cosmology · Physics 2013-05-09 Nilanjana Mahata , Subenoy Chakraborty

In this work, we study the dynamical systems analysis of phantom dark energy models considering a general potential. The stability analysis of the system shows that there is only one fixed point which could be the beginning of the universe…

General Relativity and Quantum Cosmology · Physics 2018-06-13 Nandan Roy , Nivedita Bhadra

A huge amount of good quality data converges towards the picture of a spatially flat universe undergoing the today observed phase of accelerated expansion. This new observational trend is commonly addressed as Precision Cosmology. Despite…

General Relativity and Quantum Cosmology · Physics 2008-12-02 S. Capozziello

A successor to the standard hot big-bang cosmology is emerging. It greatly extends the highly successful hot big-bang model. A key element of the New Standard Cosmology is dark energy, the causative agent for accelerated expansion. Dark…

Astrophysics · Physics 2007-05-23 Michael S. Turner