Optimisation of the exact renormalisation group

By D. Litim. 2000

278 citations recorded by the source corpus.

Abstract A simple criterion to optimise coarse-grainings for exact renormalisation group equations is given. It is aimed at improving the convergence of approximate solutions of flow equations. The optimisation criterion is generic, as it refers only to the coarse-grained propagator at vanishing field. In physical terms, it is understood as an optimisation condition for amplitude expansions. Alternatively, it can be interpreted as the requirement to move poles of threshold functions away from the physical region. The link to expansions in field amplitudes is discussed as well. Optimal parameters are given explicitly for a variety of different coarse-grainings. As a by-product it is found that the sharp cut-off regulator does not belong to the class of such optimal coarse-grainings, which explains the poor convergence of amplitude expansions based on it.

Subfields: Condensed Matter Physics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/3d9b29c8930cf468fffdd563208c4ccf84116f59

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In Condensed Matter Physics

1. M. Buchhold
2. S. Diehl
3. J. Andersen

In Nuclear and High Energy Physics

1. M. Buchhold
2. Lukas M. Sieberer
3. S. Diehl
4. J. Andersen

Citations in the corpus

• Keldysh field theory for driven open quantum systems (2015, background): “In fact, by choosing the following optimized form of the cutoff function [278, 279] (which obviously satisfies the requirements stated in Eqs.”