{ "id": "2211.01755", "version": "v1", "published": "2022-11-03T12:37:54.000Z", "updated": "2022-11-03T12:37:54.000Z", "title": "KMS states and their classical limit", "authors": [ "Christiaan J. F. van de Ven" ], "comment": "39 pages", "categories": [ "math-ph", "math.MP" ], "abstract": "A continuous bundle of $C^*$-algebras provides a rigorous framework to study the thermodynamic limit of quantum theories. If the bundle admits the additional structure of a strict deformation quantization (in the sense of Rieffel) one is allowed to study the classical limit of the quantum system, i.e. a mathematical formalization in which convergence of algebraic quantum states to probability measures on phase space (typically a Poisson or symplectic manifold) is studied. In this manner we first prove the existence of the classical limit of Gibbs states illustrated with a class of Schr\\\"{o}dinger operators in the regime where Planck's constant $\\hbar$ appearing in front of the Laplacian approaches zero. We additionally show that the ensuing limit corresponds to the unique probability measure satisfying the so-called classical or static KMS- condition. Subsequently, a similar study is conducted for the free energy in the classical limit of mean-field quantum spin systems in the regime of large particles, and the existence of the classical limit of the relevant Gibbs states is discussed.", "revisions": [ { "version": "v1", "updated": "2022-11-03T12:37:54.000Z" } ], "analyses": { "keywords": [ "classical limit", "kms states", "mean-field quantum spin systems", "unique probability measure", "laplacian approaches zero" ], "note": { "typesetting": "TeX", "pages": 39, "language": "en", "license": "arXiv", "status": "editable" } } }