D-term strings

TL;DR

This paper investigates D-term cosmic strings within N=1 supergravity, demonstrating their supersymmetric properties, relation to string theory D1-strings, and implications for non-BPS backgrounds and brane-anti-brane systems.

Contribution

It provides a detailed analysis of D-term string solutions in supergravity, establishing their supersymmetry, connection to D1-strings, and insights into non-BPS string backgrounds.

Findings

D-term strings preserve half of the supersymmetry.

D-term strings are conjectured to describe D1-strings in string theory.

Insights into supersymmetry breaking and brane-anti-brane systems.

Abstract

We study the embedding of cosmic strings, related to the Abrikosov-Nielsen-Olesen vortex solution, into d=4, N=1 supergravity. We find that the local cosmic string solution which saturates the BPS bound of supergravity with $D$-term potential for the Higgs field and with constant Fayet--Iliopoulos term, has 1/2 of supersymmetry unbroken. We observe an interesting relation between the gravitino supersymmetry transformation, positive energy condition and the deficit angle of the cosmic string. We argue that the string solutions with magnetic flux with F-term potential cannot be supersymmetric, which leads us to a conjecture that D1-strings (wrapped D(1+q)-branes) of string theory in the effective 4d supergravity are described by the D-term strings that we study in this paper. We give various consistency checks of this conjecture, and show that it highlights some generic properties of non-BPS string theory backgrounds, such as brane-anti-brane systems. Supersymmetry breaking by such systems can be viewed as FI D-term breaking, which implies, under certain conditions, the presence of gauged R-symmetry on such backgrounds. The D-term nature of the brane-anti-brane energy can also provide information on the superpotential for the tachyon, which Higgses the R-symmetry. In this picture, the inter-brane force can be viewed as a result of the world-volume gauge coupling renormalization by the open string loops.