Estimates of Green functions and harmonic measures for elliptic operators with singular drift terms

Abstract

In this paper, we prove the existence and uniqueness of the continuous Green function G for the elliptic operator L = div(A(x)∇x)+B(x)·∇x with singular drift term B on a C1,1 bounded domain D in Rn, n ≥ 3, and its comparability to the Green function G0 of L0 = div(A(x)∇x). Basing on this result we establish the equivalence of the L-harmonic measure and the surface measure on ∂D. These results extend some first ones proved for elliptic operators with less singular drift terms.