{ "id": "2201.08777", "version": "v1", "published": "2022-01-21T16:51:51.000Z", "updated": "2022-01-21T16:51:51.000Z", "title": "Generalizations of results of Friedman and Washington on cokernels of random $p$-adic matrices", "authors": [ "Gilyoung Cheong", "Nathan Kaplan" ], "comment": "17 pages", "categories": [ "math.NT", "math.CO", "math.PR" ], "abstract": "Let $p$ be prime and $X$ be a Haar-random $n \\times n$ matrix over $\\mathbb{Z}_{p}$, the ring of $p$-adic integers. Let $P_{1}(t), \\dots, P_{l}(t) \\in \\mathbb{Z}_{p}[t]$ be monic polynomials of degree at most $2$ whose images modulo $p$ are distinct and irreducible in $\\mathbb{F}_{p}[t]$. For each $j$, let $G_{j}$ be a finite module over $\\mathbb{Z}_{p}[t]/(P_{j}(t))$. We show that as $n$ goes to infinity, the probabilities that $\\mathrm{cok}(P_{j}(X)) \\simeq G_{j}$ are independent, and each probability can be described in terms of a Cohen-Lenstra distribution. We also show that for any fixed $n$, the probability that $\\mathrm{cok}(P_{j}(X)) \\simeq G_{j}$ for each $j$ is a constant multiple of the probability that that $\\mathrm{cok}(P_{j}(\\bar{X})) \\simeq G_{j}/pG_{j}$ for each $j$, where $\\bar{X}$ is an $n \\times n$ uniformly random matrix over $\\mathbb{F}_{p}$. These results generalize work of Friedman and Washington and prove new cases of a conjecture of Cheong and Huang.", "revisions": [ { "version": "v1", "updated": "2022-01-21T16:51:51.000Z" } ], "analyses": { "keywords": [ "adic matrices", "washington", "generalizations", "probability", "finite module" ], "note": { "typesetting": "TeX", "pages": 17, "language": "en", "license": "arXiv", "status": "editable" } } }