Field-theoretical results on transitions with complex symmetries
Pasquale Calabrese


Abstract
The quantitative description of many continuos phase transtions can be obtained by considering an effective Landau-Ginzburg Hamiltonian, having an $N$-component order parameter. We perform high-order perturbative computation in fixed-dimension and $epsilon$-expansion framework. We apply this approach to several critical phenomena: i) We study the combined effects of cubic anisotropy and quenched uncorrelated impurities. ii) We study the multicritical behavior arising from the competition of two distinct types of ordering. We discuss the relevance of these results in physically interesting systems, in particular for anisotropic antifferromagnet in a magnetic field and for the $SO(5)$ theory of high-$T_c$ superconductors.

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Elenco dei partecipanti al convegno di Bari.

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