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arXiv · hep-th/9403164

Two loop results from one loop computations and non perturbative solutions of exact evolution equations

T. Papenbrock·C. Wetterich
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Abstract

A nonperturbative method is proposed for the approximative solution of the exact evolution equation which describes the scale dependence of the effective average action. It consists of a combination of exact evolution equations for independent couplings with renormalization group improved one loop expressions of secondary couplings. Our method is illustrated by an example: We compute the beta-function of the quartic coupling lambda of an O(N) symmetric scalar field theory to order lambda^3 as well as the anomalous dimension to order lambda^2 using only one loop expressions and find agreement with the two loop perturbation theory. We also treat the case of very strong coupling and confirm the existence of a "triviality bound".

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T. Papenbrock, C. Wetterich. 1994-03-31. Two loop results from one loop computations and non perturbative solutions of exact evolution equations. https://doi.org/10.1007/bf01556140

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