{ "id": "1601.01433", "version": "v1", "published": "2016-01-07T08:02:44.000Z", "updated": "2016-01-07T08:02:44.000Z", "title": "A generalization of Watson transformation and representations of ternary quadratic forms", "authors": [ "Jangwon Ju", "Inhwan Lee", "Byeong-Kweon Oh" ], "categories": [ "math.NT" ], "abstract": "Let $L$ be a positive definite (non-classic) ternary $\\z$-lattice and let $p$ be a prime such that a $\\frac 12\\z_p$-modular component of $L_p$ is nonzero isotropic and $4\\cdot dL$ is not divisible by $p$. For a nonnegative integer $m$, let $\\mathcal G_{L,p}(m)$ be the genus with discriminant $p^m\\cdot dL$ on the quadratic space $L^{p^m}\\otimes \\q$ such that for each lattice $T \\in \\mathcal G_{L,p}(m)$, a $\\frac 12\\z_p$-modular component of $T_p$ is nonzero isotropic, and $T_q$ is isometric to $(L^{p^m})_q$ for any prime $q$ different from $p$. Let $r(n,M)$ be the number of representations of an integer $n$ by a $\\z$-lattice $M$. In this article, we show that if $m \\le 2$ and $n$ is divisible by $p$ only when $m=2$, then for any $T \\in \\mathcal G_{L,p}(m)$, $r(n,T)$ can be written as a linear summation of $r(pn,S_i)$ and $r(p^3n,S_i)$ for $S_i \\in \\mathcal G_{L,p}(m+1)$ with an extra term in some special case. We provide a simple criterion on when the extra term is necessary, and we compute the extra term explicitly. We also give a recursive relation to compute $r(n,T)$, for any $T \\in \\mathcal G_{L,p}(m)$, by using the number of representations of some integers by lattices in $\\mathcal G_{L,p}(m+1)$ for an arbitrary integer $m$.", "revisions": [ { "version": "v1", "updated": "2016-01-07T08:02:44.000Z" } ], "analyses": { "subjects": [ "11E12", "11E20" ], "keywords": [ "ternary quadratic forms", "watson transformation", "representations", "extra term", "generalization" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160101433J" } } }