At present, the heliosphere is embedded in a warm low density interstellar cloud that belongs to a cloud system flowing through the local standard of rest with a velocity near ∼18 km s. The velocity structure of the nearest interstellar material (ISM), combined with theoretical models of the local interstellar cloud (LIC), suggest that the Sun passes through cloudlets on timescales of ≤ 10–10 y...

We confront the predicted effects of hybrid inflationary models on the Cosmic Microwave Background (CMB) with three years of Wilkinson Microwave Anisotropy Probe (WMAP) observations. Using model selection, we compare the ability of a simple flat power-law ΛCDM model to describe the data to that of hybrid inflationary models involving global or local cosmic strings, or global textures. We find t...

Grand unified theories can admit cosmic strings with fermion zero modes. Such zero modes result in the string being current-carrying and the formation of stable remnants, vortons. However, the string zero modes do not automatically survive subsequent phase transitions. In this case the vortons dissipate. It is possible that the dissipating cosmic vortons create the observed baryon asymmetry of ...

The ISM of active galaxy centers is exposed to a combination of cosmic ray, FUV and X-ray radiation. We apply PDR models to this ISM with both 'nor-mal' and highly elevated (5 × 10 −15 s −1) cosmic-ray rates and compare the results to those obtained for XDRs. Our existing PDR-XDR code is used to construct models over a 10 3 − 10 5 cm −3 density range and for 0.16-160 erg s −1 cm −2 im-pingent f...

Using a Monte Carlo code which incorporates hitherto ignored effects, the delayed mixing into the ISM of the nucleosynthetic yields of supernovae and the relationship between these yields and the supernova ejecta kinetic energy (including events with very large ejecta energies, e.g. collapsars/hypernovae), we tested the viability of the three recent evolutionary models for the origin of the spa...