{ "id": "1602.07076", "version": "v1", "published": "2016-02-23T08:09:27.000Z", "updated": "2016-02-23T08:09:27.000Z", "title": "Quasi-classical expansion of the star-triangle relation and integrable systems on quad-graphs", "authors": [ "Vladimir V. Bazhanov", "Andrew P. Kels", "Sergey M Sergeev" ], "categories": [ "math-ph", "math.MP" ], "abstract": "In this paper we give an overview of exactly solved edge-interaction models, where the spins are placed on sites of a planar lattice and interact through edges connecting the sites. We only consider the case of a single spin degree of freedom at each site of the lattice. The Yang-Baxter equation for such models takes a particular simple form called the star-triangle relation. Interestigly all known solutions of this relation can be obtained as particular cases of a single \"master solution\", which is expressed through the elliptic gamma function and have continuous spins taking values of the circle. We show that in the low-temperature (or quasi-classical) limit these lattice models reproduce classical discrete integrable systems on planar graphs previously obtained and classified by Adler, Bobenko and Suris through the consistency-around-a-cube approach. We also discuss inversion relations, the physicical meaning of Baxter's rapidity-independent parameter in the star-triangle relations and the invariance of the action of the classical systems under the star-triangle (or cube-flip) transformation of the lattice, which is a direct consequence of Baxter's Z-invariance in the associated lattice models.", "revisions": [ { "version": "v1", "updated": "2016-02-23T08:09:27.000Z" } ], "analyses": { "keywords": [ "star-triangle relation", "quasi-classical expansion", "classical discrete integrable systems", "reproduce classical discrete integrable", "quad-graphs" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "inspire": 1425880 } } }