Cosmic D- and DF-strings from D3Dbar3: Black Strings and BPS Limit

TL;DR

This paper investigates D- and DF-strings in a D3-Dbar3 system, revealing gravitating black string solutions, BPS limits, and geometric properties like deficit angles, advancing understanding of string configurations in curved spacetime.

Contribution

It introduces gravitating black string solutions and analyzes BPS limits for D- and DF-strings, including their geometric and physical properties in curved spacetime.

Findings

Existence of black string solutions with horizons along the equator.

Derivation of BPS sum rule for multi-string configurations.

Identification of a maximum deficit angle of π in conical geometries.

Abstract

We study D- and DF-strings in a D3${\bar {\rm D}}3$ system by using Dirac-Born-Infeld type action. In the presence of an electric flux from the transverse direction, we discuss gravitating thick D-string solutions of a spatial manifold, ${\rm S}^{2}\times {\rm R}^{1}$, in which straight D-strings stretched along the R${}^{1}$ direction are attached to the south and north poles of the two-sphere. There is a horizon along its equator, which means the structure of black strings is formed. We also discuss the BPS limit for thin parallel D- and DF-strings in both flat and curved spacetime. We obtain the BPS sum rule for an arbitrarily-separated multi-string configuration with a Gaussian type tachyon potential. At the site of each thin BPS D(F)-string, the pressure takes a finite value. We find that there exists a maximum deficit angle $\pi$ in the conical geometry induced by thin BPS D- and DF-strings.