Estimates of the Caccioppoli-Schauder type are proven for a class of regular oblique derivative problems in Holder function spaces with weights. Previous restrictions on the range of admissible weights are showed to be unnecessary. 1. NOTATION Let c be a bounded open subset of a finite-dimensional Euclidean space. We adopt traditional notation for (real) function spaces such as Ck (ni), Ck, (j), Cck(co) , LP(c) , which need not be illustrated. We do however specify that Wk,P(co) denotes the Sobolev space of order k and exponent p on c. Next, as in [1], we set Ho (co) = CO (U0) 1 Io; norm in CO(U), H() = Cka-k(), IIa; = norm in Ckak(,k) for k (a nonnegative integer) O to, being the set of points of c whose distance from 0c is > a. Of course, Ha)(ca ) -= H a (H )(C) c Ha7)(co) if b' 0}, So{x E R N: lxI < 1, XN = O}, S+ = OB+ISa H(-b) = H(-b)(B+) , I b = Ia ,Received by the editors August 8, 1993 and, in revised form, January 27, 1994. 1991 Mathematics Subject Classification. Primary 35D10, 35J25; Secondary 35B45, 35B65, 46E35. )1995 American Mathematical Society
Read full abstract