Abstract

A theorem is proved making it possible, in certain cases, to use properties of the series $$\sum\nolimits_k^\infty { = _1 c_k \varphi _k } $$ (whereϕ k is an orthonormal system in Hilbert space) to derive properties of the series $$\sum\nolimits_k^\infty { = _1 f(c_k )\varphi } _k $$ , wheref is a function of a complex variable, holomorphic in a region containing the origin and the points c1, c2,..., ck,..., and such thatf (0)=0.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call