T-duality and the weakly coupled heterotic string

TL;DR

This paper discusses T-duality in heterotic string theory, its implications for effective supergravity models, and the mechanisms for anomaly cancellation related to anomalous U(1) symmetries.

Contribution

It provides a detailed analysis of T-duality symmetry at all orders and explores anomaly structures and cancellation mechanisms in heterotic string effective theories.

Findings

T-duality is preserved to all orders in perturbation theory.

Anomalous U(1) symmetries are generically present and their anomalies are characterized.

Mechanisms for anomaly cancellation are described in detail.

Abstract

T-duality is a symmetry of the heterotic string to all orders in string perturbation theory. This results in an effective four dimensional supergravity theory with desirable features for phenomenology. T-duality, as well as, generically, an anomalous U(1), is broken by quantum anomalies of the effective field theory. The structure of the full anomaly is presented, and the mechanisms for anomaly cancellation are described.