Vector profile and gauge invariant observables of string field theory solutions for constant magnetic field background

TL;DR

This paper investigates classical solutions in open string field theory representing constant magnetic fields, analyzing their profiles and gauge invariant observables to confirm their physical properties and couplings.

Contribution

It provides a numerical analysis of string field solutions for magnetic backgrounds, demonstrating their topological features and correct closed string couplings.

Findings

Profiles are continuous on the torus despite topologically nontrivial configurations.

Solutions correctly reproduce closed string couplings to D-branes with magnetic fields.

Numerical methods reveal smooth profiles in the presence of magnetic backgrounds.

Abstract

We study profiles and gauge invariant observables of classical solutions corresponding to a constant magnetic field on a torus in open string field theory. We numerically find that the profile is not discontinuous on the torus, although the solution describes topologically nontrivial configurations in the context of low energy effective theory. From the gauge invariant observables, we show that the solution provide correct couplings of closed strings to a D-brane with constant magnetic field.