论文标题
指数riesz bases in $ l^2 $在两个间隔
Exponential Riesz bases in $L^2$ on two interval
论文作者
论文摘要
我们提供足够的条件,使指数系统成为$ l^2(e)$的riesz基础,其中$ e $是两个间隔的结合。我们证明这些条件几乎是必要的。此外,我们证明了此类系统的``额外点效应'',也就是说,可能会遇到$ l^2(e)$中的riesz基础在间隔中与riesz基础有所不同。
We give sufficient conditions for the exponential system to be a Riesz basis in $L^2(E)$, where $E$ is a union of two intervals. We show that these conditions are close to be necessary. In addition, we demonstrate ``extra point effect'' for such systems, i.e. it may happen that the Riesz basis in $L^2(E)$ differs by one point from the Riesz basis on an interval.