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arXiv math/0606395math.CA
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标准正交序列的测不准原理

Uncertainty principles for orthonormal sequences

Philippe Jaming, Alexander M. Powell

摘要:

本文的目的是对H. S. Shapiro关于$L^2 (\R)$中标准正交序列的时间-频率集中。更确切地说,夏皮罗证明,如果元素的正交序列和他们的傅里叶变换都逐点有界的一个固定的功能在$L^2(\R)$然后序列是有限的。在一个相关的结果,夏皮罗还证明,如果元素的正交序列和他们的傅里叶变换有统一的有界手段和分散然后序列是有限的。本文给出了Shapiro测不准原理中的有限标准正交序列的大小的定量界。利用长球面波函数和球码中元素个数的组合估计,得到了该码的界。扩展Riesz基地和不同的措施的时间-频率集中。

英文摘要:

The aim of this paper is to provide complementary quantitative extensions of two results of H.S. Shapiro on the time-frequency concentration of orthonormal sequences in $L^2 (\R)$. More precisely, Shapiro proved that if the elements of an orthonormal sequence and their Fourier transforms are all pointwise bounded by a fixed function in $L^2(\R)$ then the sequence is finite. In a related result, Shapiro also proved that if the elements of an orthonormal sequence and their Fourier transforms have uniformly bounded means and dispersions then the sequence is finite. This paper gives quantitative bounds on the size of the finite orthonormal sequences in Shapiro's uncertainty principles. The bounds are obtained by using prolate spheroïdal wave functions and combinatorial estimates on the number of elements in a spherical code. Extensions for Riesz bases and different measures of time-frequency concentration are also given.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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