6 papers
Dynamical systems in perturbative scalar field cosmology
Artur Alho, Claes Uggla, John Wainwright
We derive a new \emph{regular} dynamical system on a 3-dimensional \emph{compact} state space describing linear scalar perturbations of spatially flat Robertson-Walker geometries f…
Global dynamics of Yang-Mills field and perfect-fluid Robertson-Walker cosmologies
Artur Alho, Vitor Bessa, Filipe C. Mena
We apply a new global dynamical systems formulation to flat Robertson-Walker cosmologies with a massless and massive Yang-Mills field and a perfect-fluid with linear equation of st…
Static self-gravitating Newtonian elastic balls
Artur Alho, Simone Calogero
The existence of static self-gravitating Newtonian elastic balls is proved under general assumptions on the constitutive equations of the elastic material. The proof uses methods f…
Perturbations of the Lambda-CDM model in a dynamical systems perspective
Artur Alho, Claes Uggla, John Wainwright
The observational success and simplicity of the CDM model, and the explicit analytic perturbations thereof, set the standard for any alternative cosmology. It therefore serves a…
Multi-body spherically symmetric steady states of Newtonian self-gravitating elastic matter
Artur Alho, Simone Calogero
We study the problem of static, spherically symmetric, self-gravitating elastic matter distributions in Newtonian gravity. To this purpose we first introduce a new definition of ho…
The wave equation near flat Friedmann-Lemaître-Robertson-Walker and Kasner Big Bang singularities
Artur Alho, Grigorios Fournodavlos, Anne T. Franzen
We consider the wave equation, , in fixed flat Friedmann-Lemaître-Robertson-Walker and Kasner spacetimes with topology . We obtain gen…