Viscosity methods for large deviations estimates for multiscale   stochastic processes
  We study singular perturbation problems for second order HJB equations in an unbounded setting. The main applications are large deviations estimates for the short maturity asymptotics of stochastic systems affected by a stochastic volatility, where the volatility is modelled by a process evolving at a faster time scale and satisfying some condition implying ergodicity. 
Daria Ghilli
math.AP