Rules for Localized Overlappings and Intersections of p-Branes

TL;DR

This paper derives a unified, bosonic-intersection rule for extremal p-branes localized in their relative transverse coordinates, expressing the solutions in terms of harmonic functions and showing how many known configurations arise within a single algebraic framework. It extends the analysis to bound states with a third, localized brane, introducing a non-harmonic function H_3 and a corresponding intersection rule, and demonstrates that these three-brane systems reproduce and connect to established results via dualities and reductions. The classification covers M-, NS-, and D-branes across dimensions and relates to brane setups used to study non-perturbative phenomena in supersymmetric gauge theories, while outlining future directions toward non-extremal, angled, or (p,q) web configurations. Overall, the work provides a systematic approach to constructing and organizing localized brane intersections, offering insights into their supersymmetry properties and their role in gauge/string dualities.

Abstract

We determine an intersection rule for extremal p-branes which are localized in their relative transverse coordinates by solving, in a purely bosonic context, the equations of motion of gravity coupled to a dilaton and n-form field strengths. The unique algebraic rule we obtained does not lead to new solutions while it manages to collect, in a systematic way, most of the solutions (all those compatible with our ansatz) that have appeared in the literature. We then consider bound states of zero binding energy where a third brane is accomodated in the common and overall transverse directions. They are given in terms of non-harmonic functions. A different algebraic rule emerges for these last intersections, being identical to the intersection rule for p-branes which only depend on the overall transverse coordinates. We clarify the origin of this coincidence. The whole set of solutions in ten and eleven dimensional theories is connected by dualities and dimensional reductions. They are related to brane configurations recently used to study non-perturbative phenomena in supersymmetric gauge theories.