On a criterion of belonging of entire function of exponential type to to the class $L^p$ (in Ukrainian)

Let $Е$ be a class of real entire functions of exponential type whose zeros are real and their sequence is unbounded from below and above. The foal of the paper is to prove one necessary condition that $f \in E$ belongs to the class $L^p(-\infty, \infty), p \geq 1$, i.e. $$ \int_{-\infty}^{\infty} |f(x)|^p dx < \infty, (1) $$ and that the conditions is not sufficient. The requirement of bilateral unboundedness of the sequence of zeros in the definition of class $E$ is natural, since it is necessarily fulfilled for exponential type functions from $L^p$, which follows from the well-known Lindelöf theorem [1, p.85] and from the property $f(x) \rightarrow 0$ as $|x| \rightarrow \infty$ [2, p.98].