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Related papers: Fixed points and FLRW cosmologies: Flat case

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We investigate the evolution of non vacuum Friedmann-Lema\^itre-Robertson-Walker (FLRW) with any spatial curvature in the context of Gauss-Bonnet gravity. The analysis employs a new method which enables us to explore the phase space of any…

General Relativity and Quantum Cosmology · Physics 2017-09-13 Sante Carloni , José P. Mimoso

In a recent series of papers Endean examines the properties of spatially homogeneous and isotropic (FLRW) cosmological models filled with dust in the ``conformally flat spacetime presentation of cosmology'' (CFS cosmology). This author…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Laurent Querella

We propose a finite volume scheme for a class of nonlinear parabolic equations endowed with non-homogeneous Dirichlet boundary conditions and which admit relative en-tropy functionals. For this kind of models including porous media…

Numerical Analysis · Mathematics 2017-04-21 Francis Filbet , Maxime Herda

We study the evolution of the dark energy parameter within the scope of a spatially non-flat and isotropic Friedmann-Robertson-Walker (FRW) model filled with barotropic fluid and bulk viscous stresses. We have obtained cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Hassan Amirhashchi , Anirudh Pradhan , Hishamuddin Zainuddin

Flash evaporation, a liquid-to-gas phase transition phenomenon in real fluids, is prevalent in aerospace propulsion systems. To elucidate the physical mechanisms of such complex flows and provide theoretical benchmarks for Computational…

Fluid Dynamics · Physics 2026-01-27 Haotong Bai , Ping Yi , Yixin Yang , Guoyan Zhao , Wenjia Xie , Mingbo Sun

We investigate cosmological solutions of f(R,T) modified theories of gravity for perfect fluid in spatially FLRW metric through phase space analysis, where R is Ricci scalar and T denotes the trace of energy-momentum tensor of matter…

General Relativity and Quantum Cosmology · Physics 2017-05-23 Hamid Shabani , Mehrdad Farhoudi

In this paper, we present new results on finite- and fixed-time convergence for dynamical systems using LaSalle-like invariance principles. In particular, we provide first and second-order non-smooth Lyapunov-like results for finite- and…

Optimization and Control · Mathematics 2026-03-25 Kunal Garg

We discuss the particle horizon problem in the framework of spatially homogeneous and isotropic scalar cosmologies. To this purpose we consider a Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime with possibly non-zero spatial sectional…

General Relativity and Quantum Cosmology · Physics 2019-03-21 Davide Fermi , Massimo Gengo , Livio Pizzocchero

We investigate the cosmological applications of fluids having an equation of state which is the analog to the one related to the isotropic deformation of crystalline solids, that is containing logarithmic terms of the energy density,…

General Relativity and Quantum Cosmology · Physics 2018-11-14 S. D. Odintsov , V. K. Oikonomou , A. V. Timoshkin , Emmanuel N. Saridakis , R. Myrzakulov

We present an analysis and discuss consequences of the strong correlations of the configurational parts of pressure and energy in their equilibrium fluctuations at fixed volume reported for simulations of several liquids in the companion…

Soft Condensed Matter · Physics 2009-11-13 Nicholas P. Bailey , Ulf R. Pedersen , Nicoletta Gnan , Thomas B. Schrøder , Jeppe C. Dyre

We study the decay of solutions of the wave equation in some expanding cosmological spacetimes, namely flat Friedmann-Lema\^itre-Robertson-Walker (FLRW) models and the cosmological region of the Reissner-Nordstr\"om-de Sitter (RNdS)…

General Relativity and Quantum Cosmology · Physics 2020-05-06 João L. Costa , José Natário , Pedro Oliveira

Recently we showed that in FLRW cosmology, the contribution from higher curvature terms in any generic metric gravity theory to the energy-momentum tensor is of the perfect fluid form. Such a geometric perfect fluid can be interpreted as a…

General Relativity and Quantum Cosmology · Physics 2024-08-07 Metin Gürses , Yaghoub Heydarzade , Çetin Şentürk

A low-order finite element method is constructed and analysed for an incompressible non-Newtonian flow problem with power-law rheology. The method is based on a continuous piecewise linear approximation of the velocity field and piecewise…

Numerical Analysis · Mathematics 2021-07-28 Gabriel R. Barrenechea , Endre Suli

The availability of scaling solutions in renormalisation group improved versions of cosmology are investigated in the high-energy limit. We adopt $f(R)$-type models of quantum gravity which display an interacting ultraviolet fixed point at…

General Relativity and Quantum Cosmology · Physics 2018-05-16 Kevin Falls , Daniel F. Litim , Kostas Nikolakopoulos , Christoph Rahmede

We construct the first example of finite time blow-up solutions for the heat flow of the $H$-system, describing the evolution of surfaces with constant mean curvature \begin{equation*} \left\{ \begin{aligned} &u_t = \Delta u -…

Analysis of PDEs · Mathematics 2023-11-27 Yannick Sire , Juncheng Wei , Youquan Zheng , Yifu Zhou

Recent observations suggest that the cosmological equation-of-state parameter w is close to -1. To say this is to imply that w could be slightly less than -1, which leads to R.Caldwell's "Phantom cosmologies". These often have the property…

High Energy Physics - Theory · Physics 2010-12-23 Brett McInnes

In hep-th/0506040 we discussed a classically constrained model of gravity. This theory contains known solutions of General Relativity (GR), and admits solutions that are absent in GR. Here we study cosmological implications of some of these…

High Energy Physics - Theory · Physics 2008-11-26 Gregory Gabadadze , Yanwen Shang

We develop a monotone finite volume method for the time fractional Fokker-Planck equations and theoretically prove its unconditional stability. We show that the convergence rate of this method is order 1 in space and if the space grid…

Numerical Analysis · Mathematics 2017-11-03 Yingjun Jiang , Xuejun Xu

The 2d Boussinesq equations model large scale atmospheric and oceanic flows. Whether its solutions develop a singularity in finite-time remains a classical open problem in mathematical fluid dynamics. In this work, blowup from smooth…

Analysis of PDEs · Mathematics 2015-04-08 Alejandro Sarria , Jiahong Wu

We model the large scale late time universe as a Lambda-CDM cosmology driven by cosmological constant and perfect dust fluid. Our aim is to find new solutions in the matter and Lambda epoch consistent with inflationary initial conditions,…

High Energy Physics - Theory · Physics 2013-05-29 Toby Wiseman , Benjamin Withers