An Improved Brane Anti-Brane Action from Boundary Superstring Field Theory and Multi-Vortex Solutions

TL;DR

The paper derives a fully covariant Dar{D} effective action from boundary superstring field theory that restores U(1)×U(1) gauge symmetry and encodes tachyon dynamics through the 𝔽(𝒳±√𝒴) structure. It then constructs analytic multi-vortex solutions corresponding to parallel lower-dimensional branes, showing that the RR charge μ_{p−2} and the total tension ε_{p−2} are determined by winding data and are largely insensitive to magnetic flux inside the vortices, revealing a notable degeneracy. The RR charges are shown to be topological and independent of A^−, while tensions can exhibit flux-induced degeneracies that are expected to be lifted by higher-derivative or quantum corrections. The framework is further extended to separated branes via T-duality, yielding a separation-dependent tachyon potential that mediates quantum tunneling and has implications for brane inflation and cosmic defect production.

Abstract

We present an improved effective action for the D-brane-anti-D-brane system obtained from boundary superstring field theory. Although the action looks highly non-trivial, it has simple explicit multi-vortex (i.e. codimension-2 multi-BPS D-brane) multi-anti-vortex solutions. The solutions have a curious degeneracy corresponding to different ``magnetic'' fluxes at the core of each vortex. We also generalize the brane anti-brane effective action that is suitable for the study of the inflationary scenario and the production of defects in the early universe. We show that when a brane and anti-brane are distantly separated, although the system is classically stable it can decay via quantum tunneling through the barrier.