Effective actions of non-geometric fivebranes

TL;DR

This paper derives the worldvolume actions of non-geometric fivebranes in string theory, revealing their roles as sources of non-geometric fluxes like Q flux and RR-related non-geometry, through duality transformations.

Contribution

It provides explicit DBI and WZ actions for non-geometric fivebranes, connecting their dynamics to non-geometric fluxes via duality chains.

Findings

Derived the DBI and WZ actions for non-geometric fivebranes.

Identified these branes as sources of Q flux and RR-related non-geometry.

Connected non-geometric fluxes to brane couplings through dualities.

Abstract

An interesting consequence of string dualities is that they reveal situations where the geometry of a string background appears to be globally ill-defined, a phenomenon usually referred to as non-geometry. On the other hand, string theory contains extended objects with non-trivial monodromy around them, often dubbed defect or exotic branes in co-dimension two. We determine and examine the worldvolume actions and the couplings of certain such branes. In particular, based on specific chains of T and S-dualities, we derive the DBI and WZ actions, which describe the dynamics of type IIB fivebranes as well as their couplings to the appropriate gauge potentials associated to mixed symmetry tensors. Based on these actions we discuss how these branes act as sources of non-geometric fluxes. In one case this flux is what is usually termed Q flux, associated to a T-fold compactification, while in the S-dual case a type of non-geometry related to the Ramond-Ramond sector is encountered.