Positivity of Two-Dimensional Elliptic Differential Operators with Nonlocal Conditions.

In the present paper, the differential operator A defined by ... with domain ... is considered. The Green function for A is constructed. The estimates for the Green function are obtained and the positivity of A in the Banach space C ([0,1] x R) is established. The structure of fractional spaces generated by A is investigated, the equivalence of the norm of these fractional spaces and Holder spaces is established. The positivity of A in the Holder space ... is obtained. [ABSTRACT FROM AUTHOR]