On the solvability of a linear homogeneous functional-differential equation of point type

We consider the Cauchy problem for a linear homogeneous functional-differential equation of point type on the real line. For the case of a one-dimensional equation, we obtain sufficient conditions for the existence and uniqueness of a solution with a prescribed order of growth. The spectral properties of the operator generated by the right-hand side of such an equation are studied in detail. The study relies upon a formalism based on the group properties of such equations.