ERGODICITY OF REGIME-SWITCHING FUNCTIONAL DIFFUSIONS WITH INFINITE DELAY AND APPLICATION TO A NUMERICAL ALGORITHM FOR STOCHASTIC OPTIMIZATION.

It is well known that ergodicity and the strong law of large numbers (SLLN) play important roles in stochastic control and stochastic approximations. For a class of regime-switching functional diffusion processes with infinite delay, this paper establishes exponential ergodicity in a Wasserstein distance under certain "averaging conditions." It follows from such an ergodicity property that an SLLN for additive functionals of the regime-switching diffusions is obtained based on the property of uniform mixing. Finally, an example is presented to illustrate the application of ergodicity and the SLLN to a numerical algorithm for stochastic optimization. [ABSTRACT FROM AUTHOR]