Unification of Type II Strings and T-duality

TL;DR

This paper develops a unified framework for type II string theories by doubling space-time coordinates to realize T-duality symmetries geometrically, incorporating Ramond-Ramond fields as spinors of O(10,10).

Contribution

It introduces a doubled space formulation with a generalized metric and T-duality covariant constraints, unifying type II string theories in a single geometric framework.

Findings

Realizes T-duality group O(10,10) geometrically.

Describes Ramond-Ramond fields as O(10,10) spinors.

Unifies type II theories via a doubled space approach.

Abstract

We present a unified description of the low-energy limits of type II string theories. This is achieved by a formulation that doubles the space-time coordinates in order to realize the T-duality group O(10,10) geometrically. The Ramond-Ramond fields are described by a spinor of O(10,10), which couples to the gravitational fields via the Spin(10,10) representative of the so-called generalized metric. This theory, which is supplemented by a T-duality covariant self-duality constraint, unifies the type II theories in that each of them is obtained for a particular subspace of the doubled space.