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Superfluidity within Exact Renormalisation Group approach

Boris Krippa
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Abstract

The application of the exact renormalisation group to a many-fermion system with a short-range attractive force is studied. We assume a simple ansatz for the effective action with effective bosons, describing pairing effects and derive a set of approximate flow equations for the effective coupling including boson and fermionic fluctuations. The phase transition to a phase with broken symmetry is found at a critical value of the running scale. The mean-field results are recovered if boson-loop effects are omitted. The calculations with two different forms of the regulator was shown to lead to similar results.

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Boris Krippa. 2005-12-21. Superfluidity within Exact Renormalisation Group approach. https://doi.org/10.1088/0305-4470%2F39%2F25%2Fs19

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