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arXiv · 2307.00057

Entanglement entropy of a Rarita-Schwinger field in a sphere

Valentin Benedetti·Lucas Daguerre
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Abstract

We study the universal logarithmic coefficient of the entanglement entropy (EE) in a sphere for free fermionic field theories in a $d=4$ Minkowski spacetime. As a warm-up, we revisit the free massless spin-$1/2$ field case by employing a dimensional reduction to the $d=2$ half-line and a subsequent numerical real-time computation on a lattice. Surprisingly, the area coefficient diverges for a radial discretization but is finite for a geometric regularization induced by the mutual information. The resultant universal logarithmic coefficient $-11/90$ is consistent with the literature. For the free massless spin-$3/2$ field, the Rarita-Schwinger field, we also perform a dimensional reduction to the half-line. The reduced Hamiltonian coincides with the spin-$1/2$ one, except for the omission of the lowest total angular momentum modes. This gives a universal logarithmic coefficient of $-71/90$. We discuss the physical interpretation of the universal logarithmic coefficient for free higher spin field theories without a stress-energy tensor.

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Valentin Benedetti, Lucas Daguerre. 2023-06-30. Entanglement entropy of a Rarita-Schwinger field in a sphere. https://doi.org/10.1103/physrevd.108.086015

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