Dynamics and invariant measures of multi-stochastic sine-Gordon lattices with random viscosity and nonlinear noise

We investigate mean dynamics and invariant measures for a multi-stochastic discrete sine-Gordon equation driven by random viscosity, stochastic forces, and infinite-dimensional nonlinear noise. We first show the existence of a unique solution when the random viscosity is bounded and the nonlinear diffusion of noise is locally Lipschitz continuous, which leads to the existence of a mean random dynamical system. We then prove that such a mean random dynamical system possesses a unique weak pullback mean random attractor in the Bochner space. Finally, we show the existence of an invariant measure. Some difficulties arise from dealing with the term of random viscosity in all uniform estimates (including the tail-estimate) of solutions, which lead to the tightness of a family of distribution laws of solutions.