Peter K. S. Dunsby

TL;DR: In this article, a detailed analysis of dynamics of cosmological models based on Rn gravity is presented, which can be written as a first-order autonomous system and analyzed using the standard techniques of dynamical system theory.

TL;DR: In this article, the covariant and gauge-invariant perturbations of Robertson-Walker spacetimes are compared with the coordinate-based approach of Ellis and Bruni.

TL;DR: The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over a wide range of frequencies, and with an order of magnitude greater sensitivity and survey speed than any current radio telescope as mentioned in this paper.

TL;DR: In this paper, the covariant and gauge invariant theory of scalar perturbations of a Friedmann-Lema\^{\i}tre-Robertson-Walker universe for fourth order gravity, where the matter is described by a perfect fluid with a barotropic equation of state, is presented.

TL;DR: In this article, it was shown that the only theory whose Lagrangian is a simple function of the Ricci scalar admits an exact $\ensuremath{\Lambda}\mathrm{CDM}$ expansion history, is standard general relativity with a positive cosmological constant and the only way to obtain this behavior of the scale factor for more general functions of $R$ is to add additional degrees of freedom to the matter sector.