Compactified NCOS and duality

TL;DR

This paper explores the dual descriptions of a non-commutative U(1) gauge theory on a torus, revealing how certain KK states manifest as stretched strings or D-strings, illustrating IR/UV mixing and S-duality intricacies.

Contribution

It identifies and tracks massive KK states across dualities in non-commutative and ordinary theories, highlighting their role in IR/UV mixing and S-duality.

Findings

KK states appear as stretched strings in non-commutative U(1)

KK states manifest as D-strings with winding and momentum in NCOS

IR/UV mixing is exemplified by these states

Abstract

We study four-dimensional U(1) on a non-commutative T^2 with rational Theta. This theory has dual descriptions as ordinary SYM or as NCOS. We identify a set of massive non-interacting KK states in the SYM theory and track them through the various dualities. They appear as stretched strings in the non-commutative U(1) providing another example of the IR/UV mixing in non-commutative field theories. In the NCOS these states appear as D-strings with winding and momentum. They form an unconventional type of 1/4 BPS state with the 3-brane. To obtain a consistent picture of S-duality for compactified theories it is essential to keep track of both the NS and the RR B-fields.