Y-system and Quasi-Classical Strings

TL;DR

This paper solves the Y-system equations in the strong coupling limit and demonstrates that it accurately predicts the quasi-classical string spectrum in AdS3 x S1, including finite size corrections, supporting the Y-system conjecture.

Contribution

It provides the first explicit solution of the Y-system in the strong coupling limit and confirms its accuracy in describing string spectra with finite size effects.

Findings

Y-system solutions match quasi-classical string spectra

Y-system correctly predicts finite size corrections

Supports the conjecture relating Y-system to AdS/CFT spectrum

Abstract

Recently Kazakov, Vieira and the author conjectured the Y-system set of equations describing the planar spectrum of AdS/CFT. In this paper we solve the Y-system equations in the strong coupling scaling limit. We show that the quasi-classical spectrum of string moving inside AdS3 x S1 matches precisely with the prediction of the Y-system. Thus the Y-system, unlike the asymptotic Bethe ansatz, describes correctly the spectrum of one-loop string energies including all exponential finite size corrections. This gives a very non-trivial further support in favor of the conjecture.