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arXiv · 1107.2363

On the Potts model partition function in an external field

Leslie M. McDonald·Iain Moffatt
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Abstract

We study the partition function of Potts model in an external (magnetic) field, and its connections with the zero-field Potts model partition function. Using a deletion-contraction formulation for the partition function Z for this model, we show that it can be expanded in terms of the zero-field partition function. We also show that Z can be written as a sum over the spanning trees, and the spanning forests, of a graph G. Our results extend to Z the well-known spanning tree expansion for the zero-field partition function that arises though its connections with the Tutte polynomial.

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Leslie M. McDonald, Iain Moffatt. 2012-01-26. On the Potts model partition function in an external field. https://doi.org/10.1007/s10955-012-0449-2

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