On brane–antibrane forces

Abstract

In this note, we will discuss two aspects of brane–antibrane forces. In one aspect, we generalize the force calculation of D0-0 of Banks and Susskind to Dp-p for 1 ≤ p ≤ 8. In particular, we find that the force is also divergent for p = 1 while for the other cases (p ≥ 2) the forces are in general finite when Z → 0+, where Z = (Y2)/(2π2α')−1 with Y, the brane–antibrane separation. However, the forces are divergent for all cases when Z < 0, signalling the occurrence of open string tachyon condensation in this regime. The other deals with the puzzling static nature of the supergravity brane–antibrane configurations. We will show that the force on a brane probe due to a brane–antibrane background vanishes when the probe is placed at the location of the coincident brane–antibranes, thereby providing a direct evidence for the existence of general static brane–antibrane configuration in the supergravity approximation.