Spectral properties of the operator associated with a retarded functional differential equation in Hilbert space
Jin‐Mun Jeong · Proceedings of the Japan Academy Series A Mathematical Sciences · 1989
In [4] the fundamental result on the structural operator for the linear retarded functional differential equationin a Hilbert space H was established.Here, --A0 is the operator associated with a bounded sesquilinear form a(, ) defined in VV