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arXiv · 2602.23078

Non-perturbative renormalization of the energy momentum tensor in the 2d O(3) nonlinear sigma model

Mika Lauk·Agostino Patella
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Abstract

The two-dimensional O(3) nonlinear sigma model is a well known toy model for studying non-perturbative phenomena in quantum field theory. A central challenge is the renormalization of the energy-momentum tensor, which is complicated by the nonlinear realization of the $O(3)$ symmetry leading to non-trivial operator mixing patterns, and by large discretization artifacts affecting the determination of renormalization constants. We present results for the renormalization constants in the non-singlet sector, employing a modified lattice action with shifted boundary conditions and defining the renormalized coupling through the gradient flow. With this we obtain a precise determination of the renormalization constants $z_T$ and $Z_T$

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Mika Lauk, Agostino Patella. 2026-02-26. Non-perturbative renormalization of the energy momentum tensor in the 2d O(3) nonlinear sigma model. https://arxiv.org/abs/2602.23078

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