BPS Electromagnetic Waves on Giant Gravitons

TL;DR

This work investigates 1/8-BPS giant gravitons in $AdS_5xS^5$ carrying three angular momenta and demonstrates that supersymmetry can be preserved with nonzero worldvolume gauge fields, which manifest as electromagnetic waves on the D3-brane and contribute to the BPS angular momenta. Building on the holomorphic-surface construction for giants, it derives the necessary SUSY, Gauss-law, and Bianchi conditions for gauge-field excitations and shows the total energy saturates the BPS bound ${\\mathcal{E}}=J_{12}+J_{34}+J_{56}$ when these gauge modes are included. For nearly-spherical giants, explicit gauge-field wave solutions are obtained on the Hopf-fibered $S^3$, and these modes are quantized, yielding discrete angular-momentum quanta and revealing a rich degeneracy structure of BPS states. The results illuminate how internal worldvolume gauge dynamics enrich the giant-graviton spectrum and point to extensions to plane-wave backgrounds and more intricate worldvolume topologies with potential implications for AdS/CFT state counting.

Abstract

We find new 1/8-BPS giant graviton solutions in $AdS_5 \times S^5$, carrying three angular momenta along $S^5$, and investigate their properties. Especially, we show that nonzero worldvolume gauge fields are admitted preserving supersymmetry. These gauge field modes can be viewed as electromagnetic waves along the compact D3 brane, whose Poynting vector contributes to the BPS angular momenta. We also analyze the (nearly-)spherical giant gravitons with worldvolume gauge fields in detail. Expressing the $S^3$ in Hopf fibration ($S^1$ fibred over $S^2$), the wave propagates along the $S^1$ fiber.