Abstract:
Systems of functions {Ltn[Φ(tz)]}∞0 are considered, where Φ(z)=∑∞0anzn (an≠0, n=0,1,…) is an entire function,
Ln[F]=n!2πi∫|z|=rn>max0⩽k⩽n|λk,n|F(z)dz(z−λ0,n)⋯(z−λn,n)(n=0,1,…),
and the matrix (λk,n), k=0,1,…,n, n=0,1,…,
is given.
Under various assumptions on the matrix, theorems are proved which deal with
the question of whether the systems {Ltn[Φ(tz)]}∞0 form a basis in the spaces A(|z|<R). They are conclusive in the sense that they cannot be improved without changing the hypotheses.
The basis theorems are applied to Gel'fond and Abel–Goncharov interpolation problems, which makes it possible to study the distribution of zeros of sequences of derivatives of certain classes of entire functions.
Bibliography: 16 titles.