{ "id": "2404.15063", "version": "v1", "published": "2024-04-23T14:11:21.000Z", "updated": "2024-04-23T14:11:21.000Z", "title": "On cyclotomic matrices involving Gauss sums over finite fields", "authors": [ "Hai-Liang Wu", "Jie Li", "Li-Yuan Wang" ], "comment": "This is a preliminary version", "categories": [ "math.NT" ], "abstract": "Inspired by the Carlitz's work on cyclotomic matrices, in this paper, we investigate certain cyclotomic matrices involving Gauss sums over finite fields. For example, let $q=p^n$ be an odd prime power with $p$ prime and $n\\in\\mathbb{Z}^+$. Let $\\zeta_p=e^{2\\pi{\\bf i}/p}$ and let $\\chi$ be a generator of the group of all mutiplicative characters of the finite field $\\mathbb{F}_q$. For the Gauss sum $$G_q(\\chi^{r})=\\sum_{x\\in\\mathbb{F}_q}\\chi^{r}(x)\\zeta_p^{{\\rm Tr}_{\\mathbb{F}_q/\\mathbb{F}_p}(x)},$$ we prove that $$\\det \\left[G_q(\\chi^{2i+2j})\\right]_{0\\le i,j\\le (q-3)/2}=(-1)^{\\alpha_p}\\left(\\frac{q-1}{2}\\right)^{\\frac{q-1}{2}}2^{\\frac{p^{n-1}-1}{2}},$$ where $$\\alpha_p=\\begin{cases}1 & \\mbox{if}\\ n\\equiv 1\\pmod 2, (p^2+7)/8 & \\mbox{if}\\ n\\equiv 0\\pmod 2. \\end{cases}$$", "revisions": [ { "version": "v1", "updated": "2024-04-23T14:11:21.000Z" } ], "analyses": { "keywords": [ "gauss sum", "finite field", "cyclotomic matrices", "odd prime power", "carlitzs work" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }