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arXiv · 2507.05923

Three-loop singularity structure for a non-linear sigma model

P. V. Akacevich·A. V. Ivanov·I. V. Korenev
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Abstract

The paper is devoted to the three-loop renormalization of the effective action for a two-dimensional non-linear sigma model using the background field method and a cutoff regularization in the coordinate representation. The coefficients of the renormalization constant and the necessary auxiliary vertices are found, as well as the asymptotic expansions of all three-loop diagrams, and their dependence on the type of regularizing function. A comparison is also made with the standard case of cutoff in the momentum representation.

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P. V. Akacevich, A. V. Ivanov, I. V. Korenev. 2025-07-08. Three-loop singularity structure for a non-linear sigma model. https://arxiv.org/abs/2507.05923

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