Abstract of a paper by Th. Schlumprecht and N. Sivakumar
This is an announcement for the paper "On the sampling and recovery of bandlimited functions via scattered translates of the Gaussian" by Th. Schlumprecht and N. Sivakumar. Abstract: Let $\lambda$ be a positive number, and let $(x_j:j\in\mathbb Z)\subset\mathbb R$ be a fixed Riesz-basis sequence, namely, $(x_j)$ is strictly increasing, and the set of functions $\{\mathbb R\ni t\mapsto e^{ix_jt}:j\in\mathbb Z\}$ is a Riesz basis ({\it i.e.,\/} unconditionalbasis) for $L_2[-\pi,\pi]$. Given a function $f\in L_2(\mathbb R)$ whose Fourier transform is zero almost everywhere outside the interval $[-\pi,\pi]$, there is a unique square-summable sequence $(a_j:j\in\mathbb Z)$, depending on $\lambda$ and $f$, such that the function$$I_\lambda(f)(x):=\sum_{j\in\mathbb Z}a_je^{-\lambda(x-x_j)^2}, \qquad x\in\mathbb R, $$ is continuous and square integrable on $(-\infty,\infty)$, and satisfies the interpolatory conditions $I_\lambda (f)(x_j)=f(x_j)$, $j\in\mathbb Z$. It is shown that $I_\lambda(f)$ converges to $f$ in $L_2(\mathbb R)$, and also uniformly on $\mathbb R$, as $\lambda\to0^+$. A multidimensional version of this result is also obtained. In addition, the fundamental functions for the univariate interpolation process are defined, and some of their basic properties, including their exponential decay for large argument, are established. It is further shown that the associated interpolation operators are bounded on $\ell_p(\mathbb Z)$ for every $p\in[1,\infty]$. Archive classification: math.CA math.FA Mathematics Subject Classification: 41A05 46E15 The source file(s), scsi1_5.tex: 93892 bytes, is(are) stored in gzipped form as 0803.4344.gz with size 27kb. The corresponding postcript file has gzipped size 165kb. Submitted from: schlump@math.tamu.edu The paper may be downloaded from the archive by web browser from URL http://front.math.ucdavis.edu/0803.4344 or http://arXiv.org/abs/0803.4344 or by email in unzipped form by transmitting an empty message with subject line uget 0803.4344 or in gzipped form by using subject line get 0803.4344 to: math@arXiv.org.
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alspach@fourier.math.okstate.edu