Light-cone-like spreading of single-particle correlations in the Bose-Hubbard model after a quantum quench in the strong-coupling regime

We study the spreading of correlations in space and time after a quantum quench in the Bose-Hubbard model. We derive equations of motion for the single-particle Green's function within the contour-time formalism, allowing us to study dynamics in the strong-coupling regime. We discuss the numerical solutions of these equations and calculate the single-particle density matrix for quenches in the Mott phase. We demonstrate light-cone-like spreading of correlations in the Mott phase in one, two, and three dimensions and calculate the propagation velocities in each dimension.