Schnabl's Solution and Boundary States in Open String Field Theory

TL;DR

This paper explores Schnabl's solution in open string field theory, revealing its connection to boundary states and D-branes, and clarifies its physical interpretation and relation to gauge invariants.

Contribution

It demonstrates that Schnabl's solution extends boundary states off-shell and supports Ellwood's proposal, enhancing understanding of D-branes in string theory.

Findings

Schnabl's solution is an off-shell boundary state for D-branes.

It clarifies the physical meaning of gauge invariant overlaps.

Supports Ellwood's recent operator formalism proposal.

Abstract

We discuss that Schnabl's solution is an off-shell extension of the boundary state describing a D-brane in the closed string sector. It gives the physical meaning of the gauge invariant overlaps for the solution in our previous paper and supports Ellwood's recent proposal in the operator formalism.