Products involving the real parts of Jacobi sums and related cyclotomic matrices

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Wu, Hai-Liang, Ji, Xiao-Han
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866918529413939200
author Wu, Hai-Liang
Ji, Xiao-Han
author_facet Wu, Hai-Liang
Ji, Xiao-Han
contents Let $q$ be an odd prime power and $χ_q$ be a generator of the group of all multiplicative characters of $\mathbb{F}_q$. In this paper, we study the arithmetic properties of the product $$R_q(χ_q)=\prod_{0<k<(q-1)/4}\left(J_q(ϕ_q,χ_q^k)+J_q(ϕ_q,χ_q^{-k})\right),$$ which is related to the real parts of Jacobi sums. Also, we reveal the connection between $R_q$ and the cyclotomic matrix $$\left[ϕ_q(s_i+s_j)\right]_{1\le i,j\le (q-1)/2},$$ where $ϕ_q$ is the unique quadratic multiplicative character of $\mathbb{F}_q$, and $s_1,s_2,\cdots,s_{(q-1)/2}$ are exactly all non-zero squares over $\mathbb{F}_q$.
format Preprint
id arxiv_https___arxiv_org_abs_2605_27169
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Products involving the real parts of Jacobi sums and related cyclotomic matrices
Wu, Hai-Liang
Ji, Xiao-Han
Number Theory
Let $q$ be an odd prime power and $χ_q$ be a generator of the group of all multiplicative characters of $\mathbb{F}_q$. In this paper, we study the arithmetic properties of the product $$R_q(χ_q)=\prod_{0<k<(q-1)/4}\left(J_q(ϕ_q,χ_q^k)+J_q(ϕ_q,χ_q^{-k})\right),$$ which is related to the real parts of Jacobi sums. Also, we reveal the connection between $R_q$ and the cyclotomic matrix $$\left[ϕ_q(s_i+s_j)\right]_{1\le i,j\le (q-1)/2},$$ where $ϕ_q$ is the unique quadratic multiplicative character of $\mathbb{F}_q$, and $s_1,s_2,\cdots,s_{(q-1)/2}$ are exactly all non-zero squares over $\mathbb{F}_q$.
title Products involving the real parts of Jacobi sums and related cyclotomic matrices
topic Number Theory
url https://arxiv.org/abs/2605.27169