We review applications of string theory to cosmology, from primordial times to the present-
day accelerated expansion. Starting with a brief overview of cosmology and string …

In this review we present a thoroughly comprehensive survey of recent work on modified
theories of gravity and their cosmological consequences. Amongst other things, we cover …

De Sitter solutions have been recently conjectured to be incompatible with quantum gravity.
In this paper we critically assess the progress and challenges of different mechanisms to …

The observable universe could be a 1+ 3-surface (the “brane”) embedded in a 1+ 3+ d-
dimensional spacetime (the “bulk”), with Standard Model particles and fields trapped on the …

We explore a new class of braneworld models in which the scalar curvature of the (induced)
brane metric contributes to the brane action. The scalar curvature term arises generically on …

I briefly review our current understanding of dark matter and dark energy. The first part of this
review focusses on issues pertaining to dark matter including observational evidence for its …

This chapter presents a brief introduction to 'naturalness' problems in cosmology, and to the
cosmological constant problem in particular. The main focus is the 'old'cosmological …

We investigate the possibility of self-tuning of the effective 4D cosmological constant in 6D
supergravity, to see whether it could naturally be of order 1/r4 when compactified on two …

The tension between measurements of the Hubble constant obtained at different redshifts
may provide a hint of new physics active in the relatively early universe, around the epoch of …

We investigate a string-inspired dark energy scenario featuring a scalar field with a coupling
to the Gauss-Bonnet invariant. We discuss extensively the cosmological and astrophysical …