Equivalent norms in spaces of entire functions

V. È. Katsnelson

Sbornik. Mathematics, Tome 21 (1973) no. 1, pp. 33-55

Résumé

It is shown that if $E\subset\mathbf R^n$ is relatively dense with respect to Lebesgue mesure and $p\in(0,\infty)$, then for any entire function $f(z)$ of $n$ complex variables and of exponential type not exceeding $\sigma$ the inequality $$ \int_E|f(x)|^p\,dx_1\dots dx_n\geqslant c\int_{\mathbf R^n}|f(x)|^p\,dx_1\dots dx_n $$ is satisfied, where $c$ is a constant depending only on $\sigma$, $L$, $\delta$ and $p$, but not on $f(z)$, and the integrals on both sides of the inequality converge or diverge simultaneously. Bibliography: 11 titles.