{ "id": "1701.07196", "version": "v1", "published": "2017-01-25T07:54:35.000Z", "updated": "2017-01-25T07:54:35.000Z", "title": "Polynomial equations in function fields", "authors": [ "Pierre-Yves Bienvenu" ], "categories": [ "math.CO", "math.NT" ], "abstract": "The breakthrough paper of Croot, Lev, Pach \\cite{CLP} on progression-free sets in $\\Z_4^n$ introduced a polynomial method that has generated a wealth of applications, such as Ellenberg and Gijswijt's solutions to the cap set problem \\cite{EG}. Using this method, we bound the size of a set of polynomials over $\\F_q$ of degree less than $n$ that is free of solutions to the equation $\\sum_{i=1}^k a_if_i^r=0$, where the coefficients $a_i$ are polynomials that sum to 0 and the number of variables satisfies $k\\geq 2r^2+1$. The bound we obtain is of the form $q^{cn}$ for some constant $c<1$. This is in contrast to the best bounds known for the corresponding problem in the integers, which offer only a logarithmic saving, but work already with as few as $k\\geq r^2+1$ variables.", "revisions": [ { "version": "v1", "updated": "2017-01-25T07:54:35.000Z" } ], "analyses": { "keywords": [ "function fields", "polynomial equations", "cap set problem", "best bounds", "polynomial method" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }