Approximation of isometric function spaces by entire functions of exponential type

Authors

  • D.M. Bushev Lesya Ukrainka Volyn National University, 13 Voli ave., 43025, Lutsk, Ukraine https://orcid.org/0009-0002-6199-2077
  • I.V. Kal'chuk Lesya Ukrainka Volyn National University, 13 Voli ave., 43025, Lutsk, Ukraine https://orcid.org/0000-0001-8822-3716
  • Yu.I. Kharkevych Lesya Ukrainka Volyn National University, 13 Voli ave., 43025, Lutsk, Ukraine
https://doi.org/10.15330/cmp.17.2.679-692

Keywords:

isometric space, linear operator, approximation characteristic, convolution space, delta-like kernel, space of entire functions of exponential type
Published online: 2025-12-29

Abstract

In this article, sufficient conditions are established for mappings by convolution operators of spaces of function defined on the $n$-dimensional Euclidean space into spaces of entire functions of exponential type. Integral representations for these operators are obtained. Equalities of approximation characteristics in isometric functional spaces of many variables are obtained using equalities of approximation characteristics in isometric function spaces of one variable.

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How to Cite
(1)
Bushev, D.; Kal'chuk, I.; Kharkevych, Y. Approximation of Isometric Function Spaces by Entire Functions of Exponential Type. Carpathian Math. Publ. 2025, 17, 679-692.