Classical open string amplitudes from boundary string field theory

Abstract

We show that boundary string field theory realizes the minimal model of open string field theory. More precisely, we observe that the expansion of the (co)homological vector field, Q of boundary string field theory in the cohomology of its linear part reproduces the S-matrices of perturbative string theory. In mathematical terms, boundary string field theory realizes the minimal model map of the cohomological perturbation lemma.

Homotopy Algebras in String Field Theory

“…This procedure can then be applied recursively to determine all higher maps recursively. Furthermore, it can be shown that this construction is unique (see [] for more details). To summarize, what we found is that the algebraic structure implied by the underlying BV structure completely determines the action of superstring field theory, even though the precise formulation of the geometric BV structure on super moduli space in unexplored so far.…”