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arXiv · 2207.12103

Momentum Space Entanglement from the Wilsonian Effective Action

Matheus H. Martins Costa·Jeroen van den Brink·Flavio S. Nogueira·Gastão Krein
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Abstract

The entanglement between momentum modes of a quantum field theory at different scales is not as well studied as its counterpart in real space, despite the natural connection with the Wilsonian idea of integrating out the high-momentum degrees of freedom. Here, we push such connection further by developing a novel method to calculate the Rényi and entanglement entropies between slow and fast modes, which is based on the Wilsonian effective action at a given scale. This procedure is applied to the perturbative regime of some scalar theories, comparing the lowest-order results with those from the literature and interpreting them in terms of Feynman diagrams. This method is easily generalized to higher-order or nonperturbative calculations. It has the advantage of avoiding matrix diagonalizations of other techniques.

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Matheus H. Martins Costa, Jeroen van den Brink, Flavio S. Nogueira, Gastão Krein. 2022-10-03. Momentum Space Entanglement from the Wilsonian Effective Action. https://doi.org/10.1103/physrevd.106.065024

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