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Approximation and Interpolation by Entire Functions of Several Variables

Published online by Cambridge University Press:  20 November 2018

Maxim R. Burke*
Affiliation:
Department of Mathematics and Statistics, University of Prince Edward Island, Charlottetown, PE C1A 4P3 e-mail: [email protected]
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Abstract

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Let $f\,:\,{{\mathbb{R}}^{n}}\,\to \,\mathbb{R}$ be ${{C}^{\infty }}$ and let $h\,:\,{{\mathbb{R}}^{n}}\,\to \,\mathbb{R}$ be positive and continuous. For any unbounded nondecreasing sequence $\{{{c}_{k}}\}$ of nonnegative real numbers and for any sequence without accumulation points $\{{{x}_{m}}\}$ in ${{\mathbb{R}}^{n}}$, there exists an entire function $g\,:\,{{\mathbb{C}}^{n}}\,\to \,\mathbb{C}$ taking real values on ${{\mathbb{R}}^{n}}$ such that

$$\left| {{g}^{\left( \alpha \right)}}\left( x \right)-{{f}^{\left( \alpha \right)}}\left( x \right) \right|\text{ }<h\left( x \right),\left| x \right|\ge {{c}_{k}},\left| \alpha \right|\le k,k=0,1,2,...,$$

$${{g}^{\left( \alpha \right)}}\left( {{x}_{m}} \right)\,=\,{{f}^{\left( \alpha \right)}}\left( {{x}_{m}} \right),\,\,\,\left| {{x}_{m}} \right|\,\ge \,{{c}_{k}},\,\left| \alpha \right|\,\le \,k,\,m,\,k\,=\,0,\,1,\,2,\,.\,.\,.\,.$$

This is a version for functions of several variables of the case $n\,=\,1$ due to $L$. Hoischen.

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 2010

References

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