• Publications
  • Influence
Dynamics of dark energy
We review in detail a number of approaches that have been adopted to try and explain the remarkable observation of our accelerating universe. In particular we discuss the arguments for and recent
Cosmic F- and D-strings
Macroscopic fundamental and Dirichlet strings have several potential instabilities: breakage, tachyon decays, and confinement by axion domain walls. We investigate the conditions under which
Exponential potentials and cosmological scaling solutions
Scalar fields have come to play a central role in current models of the early universe. The self-interaction potential energy density of such a field is undiluted by the expansion of the universe and
Quintessence arising from exponential potentials
We demonstrate how the properties of the attractor solutions of exponential potentials can lead to models of quintessence with the currently observationally favored equation of state. Moreover, we
Model independent approach to the dark energy equation of state
The consensus of opinion in cosmology is that the Universe is currently undergoing a period of accelerated expansion. With current and proposed high precision experiments it offers the hope of being
Reconstructing the inflaton potential—an overview
The authors review the relation between the inflationary potential and the spectra of density waves (scalar perturbations) and gravitational waves (tensor perturbations) produced, with particular
Quintessence models in supergravity
Scalar field models of quintessence typically require that the expectation value of the field today be of the order of the Planck mass, if we want them to explain the observed acceleration of the
General second order scalar-tensor theory, self tuning, and the Fab Four
Starting from the most general scalar-tensor theory with second order field equations in four dimensions, we establish the unique action that will allow for the existence of a consistent selftuning
Self-tuning and the derivation of a class of scalar-tensor theories
We have recently proposed a special class of scalar tensor theories known as the Fab Four. These arose from attempts to analyse the cosmological constant problem within the context of Horndeski's