On the smoothness of the solution to a boundary value problem for a differential-difference equation

This paper deals with the first boundary value problem (BVP) for equations which are a differential with respect to one variable (t) and difference with respect to the other variable (s) in a bounded domain. The initial value problem for differential-difference equations of this type was studied. The theory of the BVP under investigation is connected with the theory of the BVP for strongly elliptic differential-difference equations which are difference and differential with respect to the same variable. Some questions of this work were considered in earleir papers. Section 1 considers the solvability of the BVP for differential-difference equations. In contrast to differential equations the smoothness of the generalized solutions can be broken in the domain Q and is preserved only in some subdomains Q_r is contained in Q where (union _r anti Q_r = anti Q). In section 2 we construct such a set of Q_r. Section 3 deals with the smoothness of generalized solutions in the subdomains Q_r. Section 4 considers the conditions under which the smoothness is preserved when passing the boundaries between neighboring subdomains Q_r. (orig.)Available from TIB Hannover: RR 5549(59)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman