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Related papers: Non-linear stability of $\alpha'$-corrected Friedm…

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We consider an inverse problem for the nonlinear Boltzmann equation with a time-dependent kernel in dimensions $n\ge 2$. We establish a logarithm-type stability result for the collision kernel from measurements under certain additional…

Analysis of PDEs · Mathematics 2023-09-08 Ru-Yu Lai , Lili Yan

We investigate the impact of conformal transformations on the physical properties of solution trajectories in nonmetricity gravity. Specifically, we explore the phase-space and reconstruct the cosmological history of a spatially flat…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Nikolaos Dimakis , Kevin Duffy , Alex Giacomini , Alexander Yu. Kamenshchik , Genly Leon , Andronikos Paliathanasis

We use the Hamiltonian formulation of kinetic theory to perform a stability analysis of non-thermal fixed points in a non-Abelian plasma. We construct a perturbative expansion of the Fokker-Planck collision kernel in an adiabatic…

High Energy Physics - Phenomenology · Physics 2022-07-01 Aleksandr N. Mikheev , Aleksas Mazeliauskas , Jürgen Berges

We prove stability results for nonlinear diffusion equations of the porous medium and fast diffusion types with respect to the nonlinearity power $m$: solutions with fixed data converge in a suitable sense to the solution of the limit…

Analysis of PDEs · Mathematics 2013-09-04 Teemu Lukkari

The $\alpha'$-complete cosmology developed by Hohm and Zwiebach classifies the ${\rm O}(d,d;{\mathbb R})$ invariant theories involving metric, $b$-field and dilaton that only depend on time, to all orders in $\alpha'$. Some of these…

High Energy Physics - Theory · Physics 2021-03-17 Carmen A. Núñez , Facundo Emanuel Rost

We study the asymptotic stability of de Sitter spacetime with respect to non-linear perturbations, by considering second order perturbations of a flat Robertson-Walker universe with dust and a positive cosmological constant. Using the…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Marco Bruni , Filipe C. Mena , Reza Tavakol

Time-decaying perturbations of nonlinear oscillatory systems in the plane are considered. It is assumed that the unperturbed systems are non-isochronous and the perturbations oscillate with an asymptotically constant frequency. Resonance…

Dynamical Systems · Mathematics 2023-10-10 Oskar A. Sultanov

We prove nonlinear stability for a large class of solutions to the Einstein equations with a positive cosmological constant and compact spatial topology in arbitrary dimensions, where the spatial metric is Einstein with either positive or…

Differential Geometry · Mathematics 2018-05-01 David Fajman , Klaus Kroencke

Increasingly accurate observations are driving theoretical cosmology toward the use of more sophisticated descriptions of matter and the study of nonlinear perturbations of FL cosmologies, whose governing equations are notoriously…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Claes Uggla , John Wainwright

Non-linear nature of Einstein equation introduces genuine relativistic higher order corrections to the usual Newtonian fluid equations describing the evolution of cosmological perturbations. We study the effect of such novel non-linearities…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Donghui Jeong , Jinn-Ouk Gong , Hyerim Noh , Jai-chan Hwang

We present a novel approach, based entirely on the gravitational potential, for studying the evolution of non-linear cosmological matter perturbations. Starting from the perturbed Einstein equations, we integrate out the non-relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Ram Brustein , Antonio Riotto

We consider multidimensional gravitational models with a nonlinear scalar curvature term and form fields in the action functional. In our scenario it is assumed that the higher dimensional spacetime undergoes a spontaneous compactification…

High Energy Physics - Theory · Physics 2007-05-23 U. Guenther , P. Moniz , A. Zhuk

In this paper we study cosmological solutions to the Einstein--Euler equations. We first establish the future stability of nonlinear perturbations of a class of homogeneous solutions to the relativistic Euler equations on fixed linearly…

Analysis of PDEs · Mathematics 2024-07-25 David Fajman , Maximilian Ofner , Todd A. Oliynyk , Zoe Wyatt

We study inhomogeneous cosmological variations in the fine structure 'constant', $\alpha ,$ in Friedmann universes. Inhomogeneous motions of the scalar field driving changes in $\alpha $ display spatial oscillations that decrease in…

Astrophysics · Physics 2009-11-07 J. D. Barrow , J. Magueijo , H. B. Sandvik

At the present paper, it is studied cosmological solutions and its stability in the frame of F(R) Horava-Lifshitz gravity. The perturbations around general spatially flat FRW solutions are analyzed and it is showed that the stability of…

High Energy Physics - Theory · Physics 2011-05-10 Diego Sáez-Gómez

We investigate the time-asymptotic stability of planar rarefaction wave for the three-dimensional Boltzmann equation, based on the micro-macro decomposition introduced in [24, 22] and our new observations on the underlying wave structures…

Analysis of PDEs · Mathematics 2019-01-25 Teng Wang , Yi Wang

The evolution of linear cosmological perturbations in modified theories of gravity is investigated assuming the Palatini formalism. It has been discussed about the stability problem in this model based on the equivalence between f(R)…

General Relativity and Quantum Cosmology · Physics 2008-06-18 Seokcheon Lee

In this paper we study well-posedness and asymptotic stability for a class of nonlinear second-order evolution equations with intermittent delay damping. More precisely, a delay feedback and an undelayed one act alternately in time. We show…

Analysis of PDEs · Mathematics 2015-07-29 Genni Fragnelli , Cristina Pignotti

This paper investigates the stability properties of a nonlinear fractional differential equation with two discrete delays and a delay-dependent coefficient. Such equations arise in various biological and control systems where temporal…

Dynamical Systems · Mathematics 2026-03-12 Pragati Dutta , Sachin Bhalekar

We study semilinear elliptic equations \begin{equation*} \begin{cases} -\Delta u = f(u) & \text{in } \Omega, \\ \partial_\nu u = 0 & \text{on } \partial\Omega, \end{cases} \end{equation*} with homogeneous Neumann boundary conditions in…

Analysis of PDEs · Mathematics 2026-03-27 Marta Calanchi , Giulio Ciraolo , Francesca Messina