A description of the algebras of analytic functions admitting localization of ideals
S. A. Apresyan
Abstract:
Let
$\mathbf D=\{z\in\mathbf C:|z|<1\}$ and let
$A_\varphi(\mathbf D)$ be the algebra of all analytic functions
$f$ in
$\mathbf D$
for which $\log|f(z)|\leqslant C_f\varphi\biggl(\dfrac{1}{1-|z|}\biggr)$,
$z\in\mathbf D$. Under in known restrictions regarding the regularity of the growth of the function
$\varphi$, one proves
THEOREM. In order that each closed ideal
$I$,
$I\subset A_\varphi(\mathbf D)$, be local, it is necessary
and sufficient that one should have
$$
\int_1^\infty\biggl(\dfrac{\varphi(x)}{x^3}\biggr)^{1/2}dx=\infty.
$$
be the algebra of all analytic functions.
Here, the localness of the ideal
$I$ means that $I=\{f\in A_\varphi(\mathbf D):k_f\geqslant k_I\}$, where
$k_f(\zeta)$ is the multiplicity of a zero of the function
$f$ at the point
$\zeta$,
$k_I(\zeta)=\min_{f\in I}k_f(\zeta)$.
UDC:
517.459.8