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A tensorial approach to the study of dualities between lattice spin models

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Author(s):
Alysson Ferreira Morais
Total Authors: 1
Document type: Master's Dissertation
Press: São Paulo.
Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
Defense date:
Examining board members:
Paulo Teotonio Sobrinho; Valdecir Marvulle; Walter Alberto de Siqueira Pedra
Advisor: Paulo Teotonio Sobrinho
Abstract

In this work, we study the dualities between spin models in two-dimensional lattices from a tensorial approach. In this approach, we associate tensor components to the vertices and links so that the partition function Z is constructed by a contraction of the indices of the tensor components thereby making Z a scalar under change of basis of the group algebra C[G] used to de_ne the tensors. Having obtained this, and noting that the values of the components _x the studied model, we obtain a di_erent model for each basis transformation proposed. These di_erent models, however, have the same partition function since Z is invariant under these transformations. In fact we can obtain several models all dual to each other in this manner. We then focus on Zn spin models, which include the Ising model, the Potts model and Ashkin- Teller-Potts model. Exploring a speci_c basis transformation, we are able to rederive Kramers and Wanniers\' duality for the Ising model. With analogous arguments, we also show that Potts models with n = 3 and n = 4 are self-dual whereas this property is lost for n _ 5. The Ashkin-Teller-Potts model is shown to be self-dual for all n 2 N. (AU)

FAPESP's process: 13/02662-0 - Dualities in lattice Gauge theories
Grantee:Alysson Ferreira Morais
Support Opportunities: Scholarships in Brazil - Master