Limit joint distributions of SYK Models with partial interactions, Mixed q-Gaussian Models and Asymptotic $\varepsilon$-freeness

Abstract: We study the joint distribution of SYK Hamiltonians for different systems with specified overlaps. We show that, in the large-system limit, their joint distribution converges in distribution to a mixed $q$-Gaussian system. We explain that the graph product of diffusive abelian von Neumann algebras is isomorphic to a $W^*$-probability space generated by the corresponding $\varepsilon$-freely independent random variables with semicircular laws which form a special case of mixed $q$-Gaussian systems that can be approximated by our SYK Hamiltonian models. Thus, we obtain a random model for asymptotic $\varepsilon$-freeness.