34 citations · 88 across the 5 of their papers we have counts for
4 papers · 1 filter
Geodesics at Sudden Singularities
John D. Barrow, S. Cotsakis
We show that a general solution of the Einstein equations that describes approach to an inhomogeneous and anisotropic sudden spacetime singularity does not experience geodesic inco…
The Construction of Sudden Cosmological Singularities
John D. Barrow, S. Cotsakis, A. Tsokaros
Solutions of the Friedmann-Lemaitre cosmological equations of general relativity have been found with finite-time singularities that are everywhere regular, have regular Hubble exp…
Adiabatic invariants and Mixmaster catastrophes
S. Cotsakis, R. L. Lemmer, P. G. L. Leach
We present a rigorous analysis of the role and uses of the adiabatic invariant in the Mixmaster dynamical system. We propose a new invariant for the global dynamics which in some r…
Variational and conformal structure of nonlinear metric-connection gravitational lagrangians
S. Cotsakis, J. Miritzis, L. Querella
We examine the variational and conformal structures of higher order theories of gravity which are derived from a metric-connection Lagrangian that is an arbitrary function of the c…