5 papers
Is Nature Generic?
Spiros Cotsakis, Peter Leach
An introductory guide to mathematical cosmology is given focusing on the issue of the genericity of various important results which have been obtained during the last thirty or so…
Ever-expanding, Isotropizing, Quadratic Cosmologies
Spiros Cotsakis, George Flessas, Peter Leach +1
We consider some aspects of the global evolution problem of Hamiltonian homogeneous, anisotropic cosmologies derived from a purely quadratic action functional of the scalar curvatu…
Symmetry, Singularities and Integrability in Complex Dynamics IV: Painleve Integrability of Isotropic Cosmologies
John Miritzis, Peter Leach, Spiros Cotsakis
We apply the results of singularity analysis to the isotropic cosmological models in general relativity and string theory with a variety of matter terms. For some of these models t…
Symmetry, singularities and integrability in complex dynamics II: Rescaling and time-translation in two-dimensional systems
Peter Leach, Spiros Cotsakis, George Flessas
The explicit integrability of second order ordinary differential equations invariant under time-translation and rescaling is investigated. Quadratic systems generated from the line…
Characterisation of orthogonal perfect fluid cosmological spacetimes
Naresh Dadhich, L. K. Patel, K. S. Govinder +1
We consider the general orthogonal metric separable in space and time variables in comoving coordinates. We then characterise perfect fluid models admitted by such a metric. It tur…