Size of orthogonal sets of exponentials for the disk
Size of orthogonal sets of exponentials for the disk
复制标题
磁盘正交指数集的大小
DOI:
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发表时间:
2011
期刊:
影响因子:
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通讯作者:
M. N. Kolountzakis
中科院分区:
文献类型:
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作者:
A. Iosevich;M. N. Kolountzakis
Suppose $Lambda subseteq RR^2$ has the property that any two exponentials with frequency from $Lambda$ are orthogonal in the space $L^2(D)$, where $D subseteq RR^2$ is the unit disk. Such sets $Lambda$ are known to be finite but it is not known if their size is uniformly bounded. We show that if there are two elements of $Lambda$ which are distance $t$ apart then the size of $Lambda$ is $O(t)$. As a consequence we improve a result of Iosevich and Jaming and show that $Lambda$ has at most $O(R^{2/3})$ elements in any disk of radius $R$.