On Type IIB Vacua With Varying Coupling Constant

TL;DR

This paper explores type IIB string theory compactifications with a varying coupling constant, extending F-theory vacua to include dual heterotic theories with reduced gauge bundle rank, and describes their moduli spaces.

Contribution

It introduces new classes of type IIB vacua with monodromies breaking SL(2,Z) symmetry, linking them to heterotic compactifications with reduced rank and complex geometric moduli spaces.

Findings

Extended F-theory vacua with Gamma_0(n) or Gamma(n) monodromy.

Duality to heterotic theories with reduced gauge bundle rank.

Description of heterotic moduli space via complex geometries.

Abstract

We describe type IIB compactifications with varying coupling constant in d=6,7,8,9 dimensions, where part of the ten-dimensional SL(2,Z) symmetry is broken by a background with Gamma_0(n) or Gamma(n) monodromy for n=2,3,4. This extends the known class of F-theory vacua to theories which are dual to heterotic compactifications with reduced rank. On compactifying on a further torus, we obtain a description of the heterotic moduli space of G bundles over elliptically fibered manifolds without vector structure in terms of complex geometries.