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arXiv · hep-ph/9308265

The Exact Renormalisation Group and Approximate Solutions

Tim R. Morris
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Abstract

We investigate the structure of Polchinski's formulation of the flow equations for the continuum Wilson effective action. Reinterpretations in terms of I.R. cutoff greens functions are given. A promising non-perturbative approximation scheme is derived by carefully taking the sharp cutoff limit and expanding in `irrelevancy' of operators. We illustrate with two simple models of four dimensional $λφ^4$ theory: the cactus approximation, and a model incorporating the first irrelevant correction to the renormalized coupling. The qualitative and quantitative behaviour give confidence in a fuller use of this method for obtaining accurate results.

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Tim R. Morris. 1993-10-08. The Exact Renormalisation Group and Approximate Solutions. https://doi.org/10.1142/s0217751x94000972

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