The Snapshot Problem for the Euler-Poisson-Darboux Equation

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Gonzalez, Fulton, Wang, Jue, Christensen, Jens, Kakehi, Tomoyuki
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866912489342500864
author Gonzalez, Fulton
Wang, Jue
Christensen, Jens
Kakehi, Tomoyuki
author_facet Gonzalez, Fulton
Wang, Jue
Christensen, Jens
Kakehi, Tomoyuki
contents The generalized Euler-Poisson-Darboux (EPD) equation with complex parameter $α$ is given by $$ Δ_x u=\frac{\partial^2 u}{\partial t^2}+\frac{n-1+2α}{t}\,\frac{\partial u}{\partial t}, $$ where $u(x,t)\in \mathscr E(\mathbb R^n\times \mathbb R)$, with $u$ even in $t$. For $α=0$ and $α=1$ the solution $u(x,t)$ represents a mean value over spheres and balls, respectively, of radius $|t|$ in $\mathbb R^n$. In this paper we consider existence and uniqueness results for the following two-snapshot problem: for fixed positive real numbers $r$ and $s$ and smooth functions $f$ and $g$ on $\mathbb R^n$, what are the conditions under which there is a solution $u(x,t)$ to the generalized EPD equation such that $u(x,r)=f(x)$ and $u(x,s)=g(x)$? The answer leads to a discovery of Liouville-like numbers related to Bessel functions, and we also study the properties of such numbers.
format Preprint
id arxiv_https___arxiv_org_abs_2507_13257
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle The Snapshot Problem for the Euler-Poisson-Darboux Equation
Gonzalez, Fulton
Wang, Jue
Christensen, Jens
Kakehi, Tomoyuki
Analysis of PDEs
35L05 (Primary), 58J45 (Secondary), 43A85 (Secondary)
The generalized Euler-Poisson-Darboux (EPD) equation with complex parameter $α$ is given by $$ Δ_x u=\frac{\partial^2 u}{\partial t^2}+\frac{n-1+2α}{t}\,\frac{\partial u}{\partial t}, $$ where $u(x,t)\in \mathscr E(\mathbb R^n\times \mathbb R)$, with $u$ even in $t$. For $α=0$ and $α=1$ the solution $u(x,t)$ represents a mean value over spheres and balls, respectively, of radius $|t|$ in $\mathbb R^n$. In this paper we consider existence and uniqueness results for the following two-snapshot problem: for fixed positive real numbers $r$ and $s$ and smooth functions $f$ and $g$ on $\mathbb R^n$, what are the conditions under which there is a solution $u(x,t)$ to the generalized EPD equation such that $u(x,r)=f(x)$ and $u(x,s)=g(x)$? The answer leads to a discovery of Liouville-like numbers related to Bessel functions, and we also study the properties of such numbers.
title The Snapshot Problem for the Euler-Poisson-Darboux Equation
topic Analysis of PDEs
35L05 (Primary), 58J45 (Secondary), 43A85 (Secondary)
url https://arxiv.org/abs/2507.13257