Sobolev orthogonal polynomials on the conic surface

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Fernandez, Lidia, Perez, Teresa, Pinar, Miguel, Xu, Yuan
Format: Preprint
Veröffentlicht: 2022
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866916045518798848
author Fernandez, Lidia
Perez, Teresa
Pinar, Miguel
Xu, Yuan
author_facet Fernandez, Lidia
Perez, Teresa
Pinar, Miguel
Xu, Yuan
contents Orthogonal polynomials with respect to the weight function $w_{β,γ}(t) = t^β(1-t)^γ$, $γ> -1$, on the conic surface $\{(x,t): \|x\| = t, \, x \in \mathbb{R}^d, \, t \le 1\}$ are studied recently, and are shown to be eigenfunctions of a second order differential operator $\mathcal{D}_γ$ when $β=-1$. We extend the setting to the Sobolev inner product, defined as the integration of the $s$-th normal derivative $\mathfrak{D} = \frac{\mathrm{d}}{\mathrm{d} t} - t^{-1} \langle x, \nabla_x\rangle$ of the cone with respect to $w_{β+s,0}$ over the conic surface, plus a sum of integrals over the rim of the cone. Our main results provide an explicit construction of an orthogonal basis and a formula for the orthogonal projection operators; the latter is used to exploit the interaction of differential operators and the projection operator, which allows us to study the convergence of the Fourier orthogonal series. The study can be regarded as an extension of the orthogonal structure to the weight function $w_{β, -s}$ for a positive integer $s$. It shows, in particular, that the Sobolev orthogonal polynomials are eigenfunctions of $\mathcal{D}_γ$ when $γ= -1$.
format Preprint
id arxiv_https___arxiv_org_abs_2209_08186
institution arXiv
publishDate 2022
record_format arxiv
spellingShingle Sobolev orthogonal polynomials on the conic surface
Fernandez, Lidia
Perez, Teresa
Pinar, Miguel
Xu, Yuan
Classical Analysis and ODEs
41A10, 42C05, 42C10, 33C45
Orthogonal polynomials with respect to the weight function $w_{β,γ}(t) = t^β(1-t)^γ$, $γ> -1$, on the conic surface $\{(x,t): \|x\| = t, \, x \in \mathbb{R}^d, \, t \le 1\}$ are studied recently, and are shown to be eigenfunctions of a second order differential operator $\mathcal{D}_γ$ when $β=-1$. We extend the setting to the Sobolev inner product, defined as the integration of the $s$-th normal derivative $\mathfrak{D} = \frac{\mathrm{d}}{\mathrm{d} t} - t^{-1} \langle x, \nabla_x\rangle$ of the cone with respect to $w_{β+s,0}$ over the conic surface, plus a sum of integrals over the rim of the cone. Our main results provide an explicit construction of an orthogonal basis and a formula for the orthogonal projection operators; the latter is used to exploit the interaction of differential operators and the projection operator, which allows us to study the convergence of the Fourier orthogonal series. The study can be regarded as an extension of the orthogonal structure to the weight function $w_{β, -s}$ for a positive integer $s$. It shows, in particular, that the Sobolev orthogonal polynomials are eigenfunctions of $\mathcal{D}_γ$ when $γ= -1$.
title Sobolev orthogonal polynomials on the conic surface
topic Classical Analysis and ODEs
41A10, 42C05, 42C10, 33C45
url https://arxiv.org/abs/2209.08186