Aspects of Semiclassical Strings in AdS$_5$

TL;DR

The paper develops a semiclassical framework for strings in AdS5 x S5 by exploiting an infinite set of classical conserved currents inherent to the nonlinear sigma model, and it shows how collective coordinates can capture semiclassical motion and quantization. It extends the analysis to the AdS5 x S5 / Z_M orbifold, where a solitonic solution is analyzed and quantized in a controlled expansion, connecting to a winding-string picture in a pp-wave limit. The approach highlights how integrable structures and conserved charges may imprint on the dual N=4 SYM at large λ and offers a practical procedure for extracting semiclassical spectra around solitons on curved backgrounds. Together, these results provide a general toolkit for semiclassical quantization around solitons and illuminate the link between worldsheet integrability, spacetime charges, and gauge-theory data in the AdS/CFT correspondence.

Abstract

We find an infinite number of conserved currents and charges in the semiclassical limit $λ\to \infty$ of string theory in AdS$_5 \times S^5$ and remark on their relevance to conserved charges in the dual gauge theory. We establish a general procedure of exploring the semiclassical limit by viewing the classical motion as collective motion in the relevant part of the configuration space. We illustrate the procedure for semiclassical expansion around solutions of string theory on AdS$_5 \times (S^5/Z_M)$.