{ "id": "1605.02490", "version": "v1", "published": "2016-05-09T09:26:47.000Z", "updated": "2016-05-09T09:26:47.000Z", "title": "Asymptotic distribution of values of isotropic quadratic forms at $S$-integral points", "authors": [ "Jiyoung Han", "Seonhee Lim", "Keivan Mallahi-Karai" ], "categories": [ "math.DS", "math.NT" ], "abstract": "We prove a generalization of a theorem of Eskin-Margulis-Mozes in an $S$-arithmetic setup: suppose that we are given a finite set of places $S$ over $\\mathbb{Q}$ containing the archimedean place, an irrational isotropic form ${\\mathbf q}$ of rank $n\\geq 4$ on $\\mathbb{Q}_S$, a product of $p$-adic intervals ${\\mathbb{I}}_p$, and a product $\\Omega$ of star-shaped sets. We show that if the real part of ${\\mathbf q}$ is not of signature $(2,1)$ or $(2,2)$, then the number of $S$-integral vectors ${\\mathbf v} \\in {\\mathsf{T}} \\Omega$ satisfying simultaneously ${\\mathbf q}({\\mathbf v}) \\in {\\mathbb{I}}_p$ for $p \\in S$ is asymptotically $ \\lambda({\\mathbf q}, \\Omega) |{\\mathbb{I}}| \\cdot \\| {\\mathsf{T}} \\|^{n-2}$, as ${\\mathsf{T}}$ goes to infinity, where $|{\\mathbb{I}}|$ is the product of Haar measures of the $p$-adic intervals ${\\mathbb{I}}_p$.", "revisions": [ { "version": "v1", "updated": "2016-05-09T09:26:47.000Z" } ], "analyses": { "keywords": [ "isotropic quadratic forms", "integral points", "asymptotic distribution", "adic intervals", "irrational isotropic form" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }