Adjoints of solution semigroups and identifiability of delay differential equations in Hilbert spacesMastinšek, Miklavž (Avtor) matematikaanalizanavadne diferencialne enačbepolgrupe operatorjevdiferencialne enačbe z zakasnitvijopolgrupe rešitevadjungirane polgrupeprepoznavnostThe paper deals with semigroups of operators associated with delay differential equation: ▫$dot{x}=Ax(t)+L_1x(t-h)+L_2x_t$▫, where ▫$A$▫ is the infinitesimal generator of an analytic semigroup on a Hilbert space ▫$X$▫ and ▫$L_1$▫, ▫$L_2$▫ are densely defined closed operators in ▫$X$▫ and ▫$L^2(-h,0;X)$▫ respectively. The adjoint semigroup of the solution semigroup of the delay differential equation is characterized. Eigenspaces of the generator of the adjoint semigroup are studied and the identifiability of parameters of the equation is given.19942015-07-10 14:46:33Delo ni kategorizirano51433sl