70 citations · 165 across the 8 of their papers we have counts for
8 papers
Integrability conditions of quasi-Newtonian cosmologies in modified gravity
Amare Abebe, Peter K. S. Dunsby, Deon Solomons
We investigate the integrability conditions of a class of shear-free perfect-fluid cosmological models within the framework of anisotropic fluid sources, applying our results to f(…
Bounce Conditions in f(R) Cosmologies
Sante Carloni, Peter K. S. Dunsby, Deon Solomons
We investigate the conditions for a bounce to occur in Friedmann-Robertson-Walker cosmologies for the class of fourth order gravity theories. The general bounce criterion is determ…
Bounce behaviour in Kantowski-Sachs and Bianchi Cosmologies
Deon Solomons, Peter Dunsby, George Ellis
Many cosmological scenarios envisage either a bounce of the universe at early times, or collapse of matter locally to form a black hole which re-expands into a new expanding univer…
Exact Inflation Braneworlds
Deon Solomons, Peter Dunsby, George Ellis
In Randall-Sundrum type braneworld cosmologies, the dynamical equations on the three-brane differ from the general relativity equations by terms that carry the effects of embedding…
A Solution to the Graceful Exit Problem in Pre-Big Bang Cosmology
G. F. R. Ellis, D. C. Roberts, D. Solomons +1
We examine the string cosmology equations with a dilaton potential in the context of the Pre-Big Bang Scenario with the desired scale factor duality, and give a generic algorithm f…
Caustics of Compensated Spherical Lens Models
G. F. R. Ellis, D. M. Solomons
We consider compensated spherical lens models and the caustic surfaces they create in the past light cone. Examination of cusp and crossover angles associated with particular sourc…