Rotating and Orbiting Strings in the Near-Horizon Brane Backgrounds

TL;DR

This paper reconstructs classical rotating and orbiting closed string solutions in near-horizon brane backgrounds using Schwarzschild coordinates, revealing simple energy-spin relations and connections to pp-wave spectra.

Contribution

It introduces explicit solutions for rotating strings in AdS5 x S5 and near-horizon brane geometries, highlighting new energy-spin relations and their link to pp-wave limits.

Findings

Explicit rotating string solutions described by elliptic functions.

Linear energy-spin relation in D5 and NS5 backgrounds.

Connection between string spectra and pp-wave geometries.

Abstract

Using the Schwarzschild-type coordinates in stead of the global ones we reconstruct the classical rotating closed string solutions in the AdS*5 x S*5 backgrounds. They are explicitly described by the Jacobi elliptic and trigonometrical functions of worldsheet coordinates. We study the orbiting closed string configurations in the near-horizon geometries of Dp, NS1 and NS5 branes, and derive the energy and spin of them, whose relation takes a simple form for short strings. Specially in the D5 and NS5 backgrounds we have a linear relation that the energy of the point-like string is proportional to the spin, which is associated with the spectrum of strings in the pp-wave geometries obtained by taking a special Penrose limit on the D5 and NS5 backgrounds.