NCOS and D-branes in Time-dependent Backgrounds

Cai, Rong-Gen; Lu, Jian-Xin; Ohta, Nobuyoshi

NCOS and D-branes in Time-dependent Backgrounds

Authors

Cai, Rong-Gen

Lu, Jian-Xin

Ohta, Nobuyoshi

Description

We study noncommutative open string (NCOS) theories realized in string theory with time-dependent backgrounds. Starting from a noncommutative Yang-Mills theory (NCYM) with a constant space-space noncommutativity but in a time-dependent background and making an S-dual transformation, we show that the resulting theory is an NCOS also in a time-dependent background but now with a time-dependent time-space noncommutativity and a time-dependent string scale. The corresponding dual gravity description is also given. A general SL(2,Z) transformation on the NCYM results in an NCOS with a time-dependent time-space noncommutativity and a constant space-space noncommutativity, and also in a time-dependent background.
12 pages, references added; v3: minor correction, to appear in PLB