Work

Notions of Fermionic Entropies for Causal Fermion Systems

Year: 2025

Type: article

Abstract: The fermionic von Neumann entropy, the fermionic entanglement entropy and the fermionic relative entropy are defined for causal fermion systems. Our definition makes use of entropy formulas for quasi-free fermionic states in terms of the reduced one-particle density operator. Our definitions are illustrated in various examples for Dirac spinors in two- and four-dimensional Minkowski space, in the Schwarzschild black hole geometry and for fermionic lattices. We review area laws for the two-dimensional diamond and a three-dimensional spatial region in Minkowski space. The connection is made to the computation of the relative entropy using modular theory.

Source: Mathematical Physics Analysis and Geometry

DOI: 10.1007/s11040-025-09505-3

Authors: Felix Finster, Robert H. Jonsson, Magdalena Lottner, Albert Much, Simone Murro