Review of AdS/CFT Integrability, Chapter III.4: Twist states and the cusp anomalous dimension

TL;DR

This paper reviews the calculation of the cusp anomalous dimension for twist operators in N=4 SYM across different coupling regimes, highlighting its importance in testing integrability methods.

Contribution

It provides a comprehensive overview of computing the cusp anomalous dimension using the asymptotic Bethe ansatz at weak, strong, and intermediate couplings.

Findings

Demonstrates the calculation of anomalous dimensions at various couplings.

Highlights the role of large Lorentz spin in testing Bethe equations.

Summarizes the significance of cusp anomalous dimension in integrability studies.

Abstract

We review the computation of the anomalous dimension of twist operators in the planar limit of N=4 SYM using the asymptotic Bethe ansatz and demonstrate how this quantity is obtained at weak, strong and intermediate values of the coupling constant. The anomalous dimension of twist operators in the limit of large Lorentz spin played a major role in the construction as well as in many tests of the asymptotic Bethe equations, this aspect of the story is emphasised.