A group theoretical approach of thermodynamic limits in spin systems

✍ Scribed by D. Arnal; J. C. Cortet

• Publisher: Springer
• Year: 1977
• Tongue: English
• Weight: 372 KB
• Volume: 1
• Category: Article
• ISSN: 0377-9017
• DOI: 10.1007/bf00399743

✦ Synopsis

We give a complete description of symmetric and phase invariant states on spin systems and construct explicitly the corresponding G.N.S. representations. We establish a correspondence between, on one hand, these states and their ergodic decomposition and, on the other hand, a class of unitary representations of E(2) X ~ and their decomposition in U.I.R. We interpret the thermodynamic limit a contraction of representations of U(2) to representations of E(2) X ~.