A Unifying Topological Action for Heterotic and Type II Superstring Theories

Abstract

The heterotic and type II superstring actions are identified in different anomaly-free decompositions of a single topological sigma-model action depending on bosonic and fermionic coordinates, $X^μ$ and $\r^A$ respectively, and of their topological ghosts. This model results from gauge-fixing the topological gauge symmetry $δX^μ= ε^μ(z,\bar z)$ ($μ=1,2,\dots, 10$) and $δ\r^α= ε^α(z,\bar z)$. ($α=1,2.\dots, 16$). From another viewpoint the heterotic and type II superstring actions emerge as two different gauge-fixings of the same closed two-form. Comments are also made concerning the possibility of relating $ρ^α$ to a Majorana-Weyl space-time spinor superpartner of $X^μ$.