Abstract
We study the orthogonal projection of homogeneous polynomials onto the space of homogeneous polyharmonic polynomials. To do this we derive the decomposition of homogeneous polynomials in terms of the Kelvin transform of derivatives of the fundamental solution \(|x|^{2-n}\) or \(\log |x|\). We consider also the vector bases of the space of homogeneous polyharmonic polynomials and study the problem of convergence of orthogonal series.
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The authors are grateful to the anonymous referees for the valuable comments and suggestions to improve the paper.
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Grzebuła, H., Michalik, S. On polyharmonic polynomials. Acta Math. Hungar. 169, 325–348 (2023). https://doi.org/10.1007/s10474-023-01323-9
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DOI: https://doi.org/10.1007/s10474-023-01323-9