Traces of Generalized Solutions of Elliptic Di erential-Di erence Equations with Degeneration
The paper is devoted to di erential-di erence equations with degeneration in a bounded domain Q ⊂ Rn. We consider di erential-di erence operators that cannot be expressed as a composition of a strongly elliptic di erential operator and a degenerated di erence operator. Instead of this, operators under consideration contain several degenerated di erence operators corresponding to di erentiation operators. Generalized solutions of such equations may not belong even to the Sobolev space W12(Q). Earlier, under certain conditions on di erence and di erentiation operators, we had obtained a priori estimates and proved that the orthogonal projection of the generalized solution onto the image of the di erence operator preserves certain smoothness inside some subdomains Qr ⊂ Q (Ur Qr = Q) instead of r the whole domain. In this paper, we prove necessary and su cient conditions in algebraic form for existence of traces on some parts of boundaries of subdomains Qr.