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Abstract: Recent developments in string inspired models of inflation suggest that D-strings are formed at the end of inflation. Within the supergravity model of D-strings there are chiral fermion zero modes for a D-string of winding n. Using the bounds on the relic vorton density, we show that D-strings with winding number are more strongly constrained than cosmic strings arising in cosmological phase transitions. The D-string tension of such vortons, if they survive until the present, has to satisfy where p is the intercommutation probability. Similarly, D-strings coupled with spectator fermions carry currents and also need to respect the above bound. D-strings with do not carry currents and evade the bound. We discuss the coupling of D-strings to supersymmetry breaking. When a single gauge group is present, we show that there is an incompatibility between spontaneous supersymmetry breaking and cosmic D-strings. We propose an alternative mechanism for supersymmetry breaking, which includes an additional , and might alleviate the problem. We conjecture what effect this would have on the fermion zero modes. [Copyright &y& Elsevier]

Abstract: Chameleon fields are scalar fields whose mass depends on the ambient matter density. We investigate the effects of these fields on the growth of density perturbations on sub-galactic scales and the formation of the first dark matter halos. Density perturbations on comoving scales go non-linear and collapse to form structure much earlier than in standard ΛCDM cosmology. The resulting mini-halos are hence more dense and resilient to disruption. We therefore expect (provided that the density perturbations on these scales have not been erased by damping processes) that the dark matter distribution on small scales would be more clumpy in chameleon cosmology than in the ΛCDM model. [Copyright &y& Elsevier]

Abstract: We consider massive half-maximal supergravity in dimensions and compactify it on a symmetric three-space. We find that the static configurations of obtained by balancing the positive scalar potential for the dilaton and the flux of a three-form through the three-sphere are unstable. The resulting cosmological evolution breaks supersymmetry and leads to an accelerated expansion in d dimensions. [Copyright &y& Elsevier]

The behaviour of the distance between two branes (the ‘radion’) in a brane-world model with a bulk scalar field is investigated. We show that the BPS conditions of supergravity ensure that the dynamics of the scalar field and the radion are not independent; we derive the four-dimensional effective action, showing that the effective theory is of scalar–tensor nature, coupling the radion to four-dimensional gravity. [Copyright &y& Elsevier]

Focuses on the effectiveness of rehabilitative intervention among aged patients with hearing disability in Cardiff, Wales. Increase in the use of hearing aids; Assessment of response rates and the prevalence of disability; Capability of simple questionnaires in identifying hearing disabilities.