{ "id": "1703.10546", "version": "v1", "published": "2017-03-30T16:02:43.000Z", "updated": "2017-03-30T16:02:43.000Z", "title": "Multidimensional divisor function on average over values of quadratic polynomial", "authors": [ "Nianhong Zhou" ], "comment": "16 pages", "categories": [ "math.NT" ], "abstract": "Let $F({\\bf x})={\\bf x}^tQ_m{\\bf x}+\\mathbf{b}^t{\\bf x}+c\\in\\mathbb{Z}[{\\bf x}]$ be a quadratic polynomial in $\\ell (\\ge 3 )$ variables ${\\bf x} =(x_{1},...,x_{\\ell})$, where $F({\\bf x})$ is positive when ${\\bf x}\\in\\mathbb{R}_{\\ge 1}^{\\ell}$, $Q_m\\in {\\rm M}_{\\ell}(\\mathbb{Z})$ is an $\\ell\\times\\ell$ matrix and its discriminant $\\det\\left(Q_m^t+Q_m\\right)\\neq 0$. It gives explicit asymptotic formulas for the following sum \\[ T_{k,F}(X)=\\sum_{{\\bf x}\\in [1,X]^{\\ell}\\cap\\mathbb{Z}^{\\ell}}\\tau_{k}\\left(F({\\bf x})\\right) \\] with the help of circle method. Here $\\tau_{k}(n)=\\#\\{(x_1,x_2,...,x_{k})\\in\\mathbb{N}^{k}: n=x_1x_2...x_{k}\\}$ with $k\\in\\mathbb{Z}_{\\ge 2}$ is the multidimensional divisor function.", "revisions": [ { "version": "v1", "updated": "2017-03-30T16:02:43.000Z" } ], "analyses": { "subjects": [ "11P55", "11L07", "11N37" ], "keywords": [ "multidimensional divisor function", "quadratic polynomial", "explicit asymptotic formulas", "circle method", "discriminant" ], "note": { "typesetting": "TeX", "pages": 16, "language": "en", "license": "arXiv", "status": "editable" } } }