UV/IR mixing, noncommutative instabilites and closed strings

Abstract

AbstractThe leading UV/IR mixing effects on noncommutative field theories modify the dispersion relations and, depending on their sign, may cause the appearance of unstable modes. For noncommutative gauge theories on D‐branes, this phenomenon is able to capture important information about the closed string spectrum of the parent string theory. We analyse noncommutative D‐branes on nonsupersymmetric orbifolds and twisted circle backgrounds. We find that the sign of the leading UV/IR mixing effects is governed by the mass gap between the lowest modes in the NSNS and RR closed string towers. For noncommutative D3‐branes at orbifolds we obtain a stronger result: a one to one correspondence between noncommutative instabilities and closed string tachyons.