Supersymmetry Enhancement of D-p-branes and M-branes
R. Kallosh, J. Kumar
TL;DR
This work analyzes how supersymmetry of classical D-p-brane and M-brane solutions is altered near their horizons, uncovering a frame- and dimension-dependent pattern of enhancement. In the string frame, D-p-branes exhibit full supersymmetry at the horizon for p ≤ 3, while in the 10d canonical frame enhancement occurs only for p = 3; M-branes in 11d show horizon enhancement for M2 and M5. The study extends to intersecting D3-branes, showing near-horizon 1/4 supersymmetry, and finds evidence for a universal class of near-horizon geometries (AdS_l × S^m × E^n) across various configurations, with throat sizes tied to entropy upon compactification. Overall, the results link horizon physics, geometric universality, and brane intersection patterns, and raise questions about the role of string vs Planck scales in supersymmetry enhancement and holographic interpretations.
Abstract
We examine the supersymmetry of classical D-brane and M-brane configurations and explain the dependence of Killing spinors on coordinates. We find that one half supersymmetry is broken in the bulk and that supersymmetry near the D-brane horizon is restored for $p\leq 3$, for solutions in the stringy frame, but only for $p=3$ in the10d canonical frame. We study the enhancement for the case of four intersecting D-3-branes in 10 dimensions and the implication of this for the size of the infinite throat of the near horizon geometry in non-compactified theory. We found some indications of universality of near horizon geometries of various intersecting brane configurations.