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Y-systems for generalised Gibbs ensembles in integrable quantum field theory

Castro-Alvaredo, O. ORCID: 0000-0003-1876-7341 (2022). Y-systems for generalised Gibbs ensembles in integrable quantum field theory. Journal of Physics A: Mathematical and Theoretical, 55(40), 405402. doi: 10.1088/1751-8121/ac9162


The thermodynamic Bethe ansatz approach to the study of integrable quantum field theories was introduced in the early 90s. Since then it has been known that the thermodynamic Bethe ansatz equations can be recast in the form of Y-systems. These Y-systems have a number of interesting properties, notably in the high-temperature limit their solutions are constants from which the central charge of the ultraviolet fixed point can be obtained and they are typically periodic functions, with period proportional to the dimension of the perturbing field. In this letter we discuss the derivation of Y-systems when the standard thermodynamic Bethe ansatz equations are replaced by generalised versions, describing generalised Gibbs ensembles. We shown that for many integrable quantum field theories, there is a large class of distinct generalised Gibbs ensembles which share the same Y-system.

Publication Type: Article
Additional Information: This is the Accepted Manuscript version of an article accepted for publication in Journal of Physics A: Mathematical and Theoretical. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at
Publisher Keywords: Generalised Gibbs Ensembles, Thermodynamic Bethe Ansatz, Integrable Quantum Field Theory, Y-Systems
Subjects: Q Science > QC Physics
Departments: School of Science & Technology > Mathematics
[img] Text - Accepted Version
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