Curves in the Fourier zeros of polytopal regions and the Pompeiu problem

Fuente: arXiv
Guardado en:
Detalles Bibliográficos
Autores principales: Kolountzakis, Mihail N., Spyridakis, Emmanuil
Formato: Preprint
Publicado: 2024
Materias:
Acceso en línea:
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
_version_ 1866910398516559872
author Kolountzakis, Mihail N.
Spyridakis, Emmanuil
author_facet Kolountzakis, Mihail N.
Spyridakis, Emmanuil
contents We prove that any finite union $P$ of interior-disjoint polytopes in ${\mathbb R}^d$ has the Pompeiu property, a result first proved by Williams [Wil76]. This means that if a continuous function $f$ on $R^d$ integrates to 0 on any congruent copy of $P$ then $f$ is identically 0. By a fundamental result of Brown, Schreiber and Taylor [BST73] this is equivalent to showing that the Fourier-Laplace transform of the indicator function of $P$ does not vanish identically on any 0-centered complex sphere in ${\mathbb C}^d$ . Our proof initially follows the recent one of Machado and Robins [MR23] who are using the Brion-Barvinok formula for the Fourier-Laplace transform of a polytope. But we simplify this method considerably by removing the use of properties of Bessel function zeros. Instead we use some elementary arguments on the growth of linear combinations of exponentials with rational functions as coefficients. Our approach allows us to prove the non-existence of complex spheres of any center in the zero-set of the Fourier-Laplace transform. The planar case is even simpler in that we do not even need the Brion-Barvinok formula. We then go further in the question of which sets can be contained in the null set of the Fourier-Laplace transform of a polytope by extending results of Engel [Eng23] who showed that rationally parametrized hypersurfaces, under some mild conditions, cannot be contained in this null-set. We show that a rationally parametrized curve which is not contained in an affine hyperplane in ${\mathbb C}^d$ cannot be contained in this null-set. Results about curves parametrized by meromorphic functions are also given.
format Preprint
id arxiv_https___arxiv_org_abs_2404_03405
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Curves in the Fourier zeros of polytopal regions and the Pompeiu problem
Kolountzakis, Mihail N.
Spyridakis, Emmanuil
Classical Analysis and ODEs
Analysis of PDEs
52B11, 42B37, 42B99
We prove that any finite union $P$ of interior-disjoint polytopes in ${\mathbb R}^d$ has the Pompeiu property, a result first proved by Williams [Wil76]. This means that if a continuous function $f$ on $R^d$ integrates to 0 on any congruent copy of $P$ then $f$ is identically 0. By a fundamental result of Brown, Schreiber and Taylor [BST73] this is equivalent to showing that the Fourier-Laplace transform of the indicator function of $P$ does not vanish identically on any 0-centered complex sphere in ${\mathbb C}^d$ . Our proof initially follows the recent one of Machado and Robins [MR23] who are using the Brion-Barvinok formula for the Fourier-Laplace transform of a polytope. But we simplify this method considerably by removing the use of properties of Bessel function zeros. Instead we use some elementary arguments on the growth of linear combinations of exponentials with rational functions as coefficients. Our approach allows us to prove the non-existence of complex spheres of any center in the zero-set of the Fourier-Laplace transform. The planar case is even simpler in that we do not even need the Brion-Barvinok formula. We then go further in the question of which sets can be contained in the null set of the Fourier-Laplace transform of a polytope by extending results of Engel [Eng23] who showed that rationally parametrized hypersurfaces, under some mild conditions, cannot be contained in this null-set. We show that a rationally parametrized curve which is not contained in an affine hyperplane in ${\mathbb C}^d$ cannot be contained in this null-set. Results about curves parametrized by meromorphic functions are also given.
title Curves in the Fourier zeros of polytopal regions and the Pompeiu problem
topic Classical Analysis and ODEs
Analysis of PDEs
52B11, 42B37, 42B99
url https://arxiv.org/abs/2404.03405