In this paper, we prove that there exists a unique solution to the Dirichlet
boundary value problem for a general class of semilinear second order elliptic
partial differential equations. Our approach is probabilistic. The theory of
Dirichlet processes and backward stochastic differential equations play a
crucial role.Comment: Published in at http://dx.doi.org/10.1214/10-AOP591 the Annals of
Probability (http://www.imstat.org/aop/) by the Institute of Mathematical
Statistics (http://www.imstat.org