Nicolò ZENONI
Yukawa Institute for Theoretical Physics, Kyoto University
Abstract
In quantum field theories that admit gravity dual, specific inequalities involving entanglement entropy between arbitrary disjoint spatial regions hold. An example is the monogamy of mutual information. Inspired by this, we investigate the analogous entropy inequalities in the Sachdev-Ye-Kitaev (SYK) model and its sparse version, in which some of the couplings are randomly set to zero with a given probability. Since these models have been argued to admit gravity duals up to a certain sparseness, it is interesting to see whether the entanglement structure changes in a sparseness-dependent manner. Rather than spatial entanglement, these models involve the entanglement among different flavors of Majorana fermions. Surprisingly, in the parameter space explored by our numerical analysis, all the known entropy inequalities are satisfied for any temperature and degree of sparseness for an arbitrary choice of flavor subregions. We provide counterexamples, such as the vector model with no randomness and the Ising model, where choices of subregions exist for which the entropy inequalities are violated.
[Based on: https://arxiv.org/pdf/2409.16641]
