Penrose Limits of Branes and Marginal Intersecting Branes

TL;DR

This paper derives explicit Penrose limit backgrounds for various brane configurations, revealing how these limits depend on the null geodesics and intersecting brane types, with implications for supersymmetric geometries.

Contribution

It provides closed-form Penrose limit metrics for near-horizon geometries of multiple branes, including intersecting configurations, expanding understanding of their null geodesic limits.

Findings

Penrose limit metrics for D1, D3, D5, NS1, NS5 branes derived

Dependence on light-cone time varies among brane types

Classified intersecting brane configurations into three Penrose limit types

Abstract

We construct the Penrose limit backgrounds in closed forms along the generic null geodesics for the near-horizon geometries of D1, D3, D5, NS1 and NS5 branes. The Penrose limit metrics of D1, D5 and NS1 have non-trivial dependence of the light-cone time coordinate, while those of D3 and NS5 have no its dependence. We study the Penrose limits on the marginal 1/4 supersymmetric configurations of standard intersecting branes, such as the NS-NS intersection of NS1 and NS5, the R-R intersections of Dp and Dq over some spatial dimensions and the mix intersections of NS5 and Dp over (p -1)-dimensional spaces. They are classified into three types that correspond to the Penrose limits of D1, D3 and D5 backgrounds.