Interacting branes, dual branes, and dyonic branes: a unifying lagrangian approach in D dimensions

TL;DR

This paper develops a covariant, Lorentz-invariant Lagrangian framework for interacting branes and dual branes in D dimensions, incorporating S-duality symmetry, Dirac-string dependencies, and applications to anomaly cancellation in string theory.

Contribution

It introduces a unifying Lagrangian approach for branes and dual branes, including a symmetric treatment of gauge potentials and new quantization conditions, extending previous results to a general covariant setting.

Findings

Provides a manifestly Lorentz-invariant and S-duality symmetric Lagrangian.

Derives Dirac-Schwinger quantization conditions for brane charges.

Applies the framework to anomaly cancellation in heterotic string theory.

Abstract

This paper presents a general covariant lagrangian framework for the dynamics of a system of closed n-branes and dual (D-n-4)-branes in D dimensions, interacting with a dynamical (n+1)-form gauge potential. The framework proves sufficiently general to include also a coupling of the branes to (the bosonic sector of) a dynamical supergravity theory. We provide a manifestly Lorentz-invariant and S-duality symmetric Lagrangian, involving the (n+1)-form gauge potential and its dual (D-n-3)-form gauge potential in a symmetric way. The corresponding action depends on generalized Dirac-strings. The requirement of string-independence of the action leads to Dirac-Schwinger quantization conditions for the charges of branes and dual branes, but produces also additional constraints on the possible interactions. It turns out that a system of interacting dyonic branes admits two quantum mechanically inequivalent formulations, involving inequivalent quantization conditions. Asymmetric formulations involving only a single vector potential are also given. For the special cases of dyonic branes in even dimensions known results are easily recovered. As a relevant application of the method we write an effective action which implements the inflow anomaly cancellation mechanism for interacting heterotic strings and five-branes in D=10. A consistent realization of this mechanism requires, in fact, dynamical p-form potentials and a systematic introduction of Dirac-strings.