Geometry and Thermodynamic Fluctuations of the Ising Model on a Bethe Lattice

Brian P. Dolan

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arXiv · cond-mat/9706238

Geometry and Thermodynamic Fluctuations of the Ising Model on a Bethe Lattice

Brian P. Dolan

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Abstract

A metric is introduced on the two dimensional space of parameters describing the Ising model on a Bethe lattice of co-ordination number q. The geometry associated with this metric is analysed and it is shown that the Gaussian curvature diverges at the critical point. For the special case q=2 the curvature reduces to an already known result for the one dimensional Ising model. The Gaussian curvature is also calculated for a general ferro-magnet near its critical point, generalising a previous result for t>0. The general expression near a critical point is compared with the specific case of the Bethe lattice and a subtlety, associated with the fact that the specific heat exponent for the Bethe lattice vanishes, is resolved.

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Brian P. Dolan. 1997-06-24. Geometry and Thermodynamic Fluctuations of the Ising Model on a Bethe Lattice. https://arxiv.org/abs/cond-mat/9706238

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