Noncommutative superconducting string

This talk consists of two parts. First, we review the process of Dp-Dp-brane annihilation, which may decay into a stable D(p--2)-brane. This ,s traditionally done by finding a vortex-like solution to the original tachyon. Inspired by GMS and HKLM's ideas, we find an alternative solution in the presence of a background B-field. In the second part, we attempt to model an object similar to Witten's superconducting string in terms of String Theory and B-fields. The idea is to begin with a D3-D3-brane configuration in Type IIB Superstring Theory. In the presence of a B-field along two spatial directions, we obtain a complex GMS soliton, which is itself a low-energy remnant of the resulting D1-brane. By using the Weyl-Wigner-Moyal correspondence and the bosonization technique, we find that this object (in the presence of left-handed spinors) is superconducting. (Author)