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arXiv · 0801.4960

Hyperbolic Hubbard-Stratonovich transformation made rigorous

Y. V. Fyodorov·Y. Wei·M. R. Zirnbauer
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Abstract

We revisit a long standing issue in the theory of disordered electron systems and their effective description by a non-linear sigma model: the hyperbolic Hubbard-Stratonovich (HS) transformation in the bosonic sector. For time-reversal invariant systems without spin this sector is known to have a non-compact orthogonal symmetry O(p,q). There exists an old proposal by Pruisken and Schaefer how to do the HS transformation in an O(p,q) invariant way. Giving a precise formulation of this proposal, we show that the HS integral is a sign-alternating sum of integrals over disjoint domains.

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Y. V. Fyodorov, Y. Wei, M. R. Zirnbauer. 2008-05-08. Hyperbolic Hubbard-Stratonovich transformation made rigorous. https://doi.org/10.1063/1.2917066

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