The Galilean nature of V-duality for noncommutative open string and Yang-Mills theories

A V-duality conjecture for noncommutative open string theories (NCOS) that result from decoupling D-branes in Lorentz-boost related backgrounds was pu t forward recently in hepth/0006013. The aim of this paper is to test the G alilean nature of this conjecture in the gravity dual setup. We start with an (F, D3) bound state Lorentz-boosted along one D3-brane direction perpend icular to the F-string, and show that insisting a decoupled NCOS allows onl y infinitesimal Lorentz boosts. In this way, it is shown that the V-duality relates a family of NCOS by Galileo boosts. Starting with a Lorentz-booste d (D1,D3) bound state, we show that a similar V-duality works for noncommut ative Yang-Mills (NCYM) theories as well. In addition, we deduce by a holog raphy argument that the running string tension, as a function of the energy scale, for NCOS (or NCYM) remains unchanged under V-duality. (C) 2001 Else vier Science B.V. All rights reserved.