On a mixed singular/switching control problem with multiples regimes

This paper studies {a} mixed singular/switching stochastic control problem for a multidimensional diffusion with multiples regimes on a bounded domain. Using probabilistic, partial differential equation (PDE) and penalization techniques, we show that the value function associated with this problem agrees with the solution to a Hamilton-Jacobi-Bellman (HJB) equation. In that way, we see that the regularity of the value function is $C^{0,1}\cap {\text{W}}_{loc}^{2,\mathrm{\infty }}$.