{ "id": "1409.4258", "version": "v1", "published": "2014-09-12T16:30:16.000Z", "updated": "2014-09-12T16:30:16.000Z", "title": "Sums of cubes with shifts", "authors": [ "Sam Chow" ], "categories": [ "math.NT" ], "abstract": "Let $\\mu_1, \\ldots, \\mu_s$ be real numbers, with $\\mu_1$ irrational. We investigate sums of shifted cubes $F(x_1,\\ldots,x_s) = (x_1 - \\mu_1)^3 + \\ldots + (x_s - \\mu_s)^3$. We show that if $\\eta$ is real, $\\tau >0$ is sufficiently large, and $s \\ge 9$, then there exist integers $x_1 > \\mu_1, \\ldots, x_s > \\mu_s$ such that $|F(\\mathbf{x})- \\tau| < \\eta$. This is a real analogue to Waring's problem. We then prove a full density result of the same flavour for $s \\ge 5$. For $s \\ge 11$, we provide an asymptotic formula. If $s \\ge 6$ then $F(\\mathbf{Z}^s)$ is dense on the reals. Given nine variables, we can generalise this to sums of univariate cubic polynomials.", "revisions": [ { "version": "v1", "updated": "2014-09-12T16:30:16.000Z" } ], "analyses": { "subjects": [ "11D75", "11E76", "11P05" ], "keywords": [ "univariate cubic polynomials", "full density result", "asymptotic formula", "real numbers", "real analogue" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2014arXiv1409.4258C" } } }