### Symmetry, Integrability and Geometry: Methods and Applications (SIGMA)

SIGMA 20 (2024), 042, 11 pages      arXiv:2401.03438      https://doi.org/10.3842/SIGMA.2024.042

### Asymptotic Expansions of Finite Hankel Transforms and the Surjectivity of Convolution Operators

Yasunori Okada a and Hideshi Yamane b
a) Graduate School of Science, Chiba University, Yayoicho 1-33, Inage-ku, Chiba, 263-8522, Japan
b) Department of Mathematical Sciences, Kwansei Gakuin University, Uegahara, Gakuen, Sanda, Hyogo, 669-1330, Japan

Received January 10, 2024, in final form May 21, 2024; Published online May 27, 2024

Abstract
A compactly supported distribution is called invertible in the sense of Ehrenpreis-Hörmander if the convolution with it induces a surjection from $\mathcal{C}^{\infty}(\mathbb{R}^{n})$ to itself. We give sufficient conditions for radial functions to be invertible. Our analysis is based on the asymptotic expansions of finite Hankel transforms. The dominant term may be the contribution from the origin or from the boundary of the support of the function. For the proof, we propose a new method to calculate the asymptotic expansions of finite Hankel transforms of functions with singularities at a point other than the origin.

Key words: convolution; asymptotic expansion; Hankel transform; invertibility.

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