{ "id": "2111.06139", "version": "v1", "published": "2021-11-11T10:46:46.000Z", "updated": "2021-11-11T10:46:46.000Z", "title": "Asymptotic distribution for pairs of linear and quadratic forms at integral vectors", "authors": [ "Jiyoung Han", "Seonhee Lim", "Keivan Mallahi-Karai" ], "comment": "23 pages", "categories": [ "math.DS", "math.NT" ], "abstract": "We study the joint distribution of values of a pair consisting of a quadratic form $q$ and a linear form $\\mathbf l$ over the set of integral vectors, a problem initiated by Dani-Margulis (1989). In the spirit of the celebrated theorem of Eskin, Margulis and Mozes on the quantitative version of the Oppenheim conjecture, we show that if $n \\ge 5$ then under the assumptions that for every $(\\alpha, \\beta ) \\in \\mathbb R^2 \\setminus \\{ (0,0) \\}$, the form $\\alpha q + \\beta \\mathbf l^2$ is irrational and that the signature of the restriction of $q$ to the kernel of $\\mathbf l$ is $(p, n-1-p)$, where $3\\le p \\le n-2$, the number of vectors $v \\in \\mathbb Z^n$ for which $\\|v\\| < T$, $a < q(v) < b$ and $c< \\mathbf l(v) < d$ is asymptotically $$ C(q, \\mathbf l)(d-c)(b-a)T^{n-3} , $$ as $T \\to \\infty$, where $C(q, \\mathbf l)$ only depends on $q$ and $\\mathbf l$. The density of the set of joint values of $(q, \\mathbf l)$ under the same assumptions is shown by Gorodnik (2004).", "revisions": [ { "version": "v1", "updated": "2021-11-11T10:46:46.000Z" } ], "analyses": { "subjects": [ "60B15" ], "keywords": [ "quadratic form", "integral vectors", "asymptotic distribution", "joint distribution", "joint values" ], "note": { "typesetting": "TeX", "pages": 23, "language": "en", "license": "arXiv", "status": "editable" } } }