ar X iv : a st ro - p h / 03 07 21 1 v 1 1 0 Ju l 2 00 3 Charged Domain Walls

ar X iv : a st ro - p h / 03 07 21 1 v 2 2 8 Ju l 2 00 3 Charged Domain Walls

In this paper we investigate Charged Domain Walls (CDW's), topological defects that acquire surface charge density Q induced by fermion states localized on the walls. The presence of an electric and magnetic field on the walls is also discussed. We find a relation in which the value of the surface charge density Q is connected with the existence of such topological defects.

ar X iv : a st ro - p h / 00 06 29 0 v 1 2 1 Ju n 20 00 Gas Rich Dwarfs from the PSS - II III . H I Profiles and Dynamical Masses

We present Arecibo neutral hydrogen data on a sample of optically selected dwarf galaxies.

ar X iv : a st ro - p h / 04 07 23 2 v 1 1 2 Ju l 2 00 4 B The Saas Fee Lectures on Strong Gravitational Lensing

ar X iv : a st ro - p h / 02 07 41 9 v 1 1 9 Ju l 2 00 2 Rarefaction Shocks , Shock Errors and Low Order of Accuracy in ZEUS

ar X iv : a st ro - p h / 04 08 01 0 v 1 3 1 Ju l 2 00 4 On the nature of the unidentified X - ray / γ - ray sources

We present a multiwavelength study of the environment of the unidentified X-ray/γ-ray sources IGR J18027−1455 and IGR J21247+5058, recently discovered by the IBIS/ISGRI instrument, onboard the INTEGRAL satellite. The main properties of the sources found inside their position error circles, give us clues about the nature of these high-energy sources.