Statistical Mechanics of Multiply Wound D-Branes

TL;DR

This paper explores the statistical mechanics behind why D-branes tend to become multiply wound, linking this behavior to effective repulsion in T-dual space and explaining how fractional charges combine into integer charges.

Contribution

It provides a theoretical explanation for the multiply winding of D-branes using T-duality and statistical mechanics, clarifying the origin of fractional charges and their integer charge configurations.

Findings

Multiply winding relates to effective brane repulsion in T-dual space.

Fractional charges on branes combine to form integer charges.

T-duality offers insight into brane configurations and entropy.

Abstract

The D-brane counting of black hole entropy is commonly understood in terms of excitations carrying fractional charges living on long, multiply-wound branes (e.g. open strings with fractional Kaluza-Klein momentum). This paper addresses why the branes become multiply wound. Since multiply wound branes are T-dual to branes evenly spaced around the compact dimension, this tendency for branes to become multiply wound can be seen as an effective repulsion between branes in the T-dual picture. We also discuss how the fractional charges on multiply wound branes conspire to always form configurations with integer charge.