Estimates of solutions to equations with aftereffect in Sobolev spaces and the basis of divided differences (Q1810188)

For the scale of Sobolev spaces with arbitrary index, the authors show that a certain specially selected system of functions constructed from a system of differential-difference equations of neutral type is a Riesz basis and obtain unimprovable estimates of their solutions. In contrast to many previous papers in this direction, the authors do not assume the separability of zeros of the characteristic quasipolynomial.