{ "id": "2002.06795", "version": "v1", "published": "2020-02-17T06:30:54.000Z", "updated": "2020-02-17T06:30:54.000Z", "title": "On the Turán number of 1-subdivision of $K_{3,t}$", "authors": [ "Tao Zhang", "Zixiang Xu", "Gennian Ge" ], "comment": "15 pages", "categories": [ "math.CO" ], "abstract": "For a graph $H$, the 1-subdivision of $H$, denoted by $H'$, is the graph obtained by replacing the edges of $H$ by internally disjoint paths of length 2. Recently, Conlon, Janzer and Lee (arXiv: 1903.10631) asked the following question: For any integer $s\\ge2$, estimate the smallest $t$ such that $\\textup{ex}(n,K_{s,t}')=\\Omega(n^{\\frac{3}{2}-\\frac{1}{2s}})$. In this paper, we consider the case $s=3$. More precisely, we provide an explicit construction giving \\begin{align*} \\text{ex}(n,K_{3,30}')=\\Omega(n^{\\frac{4}{3}}), \\end{align*} which reduces the estimation for the smallest value of $t$ from a magnitude of $10^{56}$ to the number $30$. The construction is algebraic, which is based on some equations over finite fields.", "revisions": [ { "version": "v1", "updated": "2020-02-17T06:30:54.000Z" } ], "analyses": { "subjects": [ "05C35" ], "keywords": [ "turán number", "finite fields", "smallest value", "internally disjoint paths", "explicit construction giving" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }