Pascal's Matrix, Point Counting on Elliptic Curves and Prolate Spheroidal Functions

Fuente: arXiv
Saved in:
Bibliographic Details
Main Author: Casper, W. Riley
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915479930535936
author Casper, W. Riley
author_facet Casper, W. Riley
contents The eigenvectors of the $(N+1)\times (N+1)$ symmetric Pascal matrix $T_N$ are analogs of prolate spheroidal wave functions in the discrete setting. The generating functions of the eigenvectors of $T_N$ are prolate spheroidal functions in the sense that they are simultaneously eigenfunctions of a third-order differential operator and an integral operator over the critical line $\{z\in\mathbb{C}: \text{Re}(z) = 1/2\}$. For even, positive integers $N$, we obtain an explicit formula for the generating function of an eigenvector of the symmetric pascal matrix with eigenvalue $1$. In the special case when $N=p-1$ for an odd prime $p$, we show that the generating function is equivalent modulo $p$ to $(\# E_z(\mathbb F_p)-1)^2$, where $\# E_z(\mathbb F_p)$ is the number of points on the Legendre elliptic curve $y^2 = x(x-1)(x-z)$ over the finite field $\mathbb F_p$.
format Preprint
id arxiv_https___arxiv_org_abs_2508_08494
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Pascal's Matrix, Point Counting on Elliptic Curves and Prolate Spheroidal Functions
Casper, W. Riley
Spectral Theory
Classical Analysis and ODEs
Number Theory
33C90, 11C20, 34L10, 11T06
The eigenvectors of the $(N+1)\times (N+1)$ symmetric Pascal matrix $T_N$ are analogs of prolate spheroidal wave functions in the discrete setting. The generating functions of the eigenvectors of $T_N$ are prolate spheroidal functions in the sense that they are simultaneously eigenfunctions of a third-order differential operator and an integral operator over the critical line $\{z\in\mathbb{C}: \text{Re}(z) = 1/2\}$. For even, positive integers $N$, we obtain an explicit formula for the generating function of an eigenvector of the symmetric pascal matrix with eigenvalue $1$. In the special case when $N=p-1$ for an odd prime $p$, we show that the generating function is equivalent modulo $p$ to $(\# E_z(\mathbb F_p)-1)^2$, where $\# E_z(\mathbb F_p)$ is the number of points on the Legendre elliptic curve $y^2 = x(x-1)(x-z)$ over the finite field $\mathbb F_p$.
title Pascal's Matrix, Point Counting on Elliptic Curves and Prolate Spheroidal Functions
topic Spectral Theory
Classical Analysis and ODEs
Number Theory
33C90, 11C20, 34L10, 11T06
url https://arxiv.org/abs/2508.08494