{ "id": "math/0401231", "version": "v1", "published": "2004-01-19T15:02:29.000Z", "updated": "2004-01-19T15:02:29.000Z", "title": "Linear equations with unknowns from a multiplicative group in a function field", "authors": [ "Jan-Hendrik Evertse", "Umberto Zannier" ], "comment": "15 pages, LaTeX file", "categories": [ "math.NT" ], "abstract": "Let k be an algebraically closed field of characteristic 0, let K/k be a transcendental extension of arbitrary transcendence degree and let G be a multiplicative subgroup of (K^*)^n such that (k^*)^n is contained in G, and G/(k^*)^n has finite rank r. We consider linear equations a1x1+...+anxn=1 (*) with fixed non-zero coefficients a1,...,an from K, and with unknowns (x1,...,xn) from the group G. Such a solution is called degenerate if there is a subset of a1x1,...,anxn whose sum equals 0. Two solutions (x1,...,xn), (y1,...,yn) are said to belong to the same (k^*)^n-coset if there are c1,...,cn in k^* such that y1=c1*x1,...,yn=cn*xn. We show that the non-degenerate solutions of (*) lie in at most 1+C(3,2)^r+C(4,2)^r+...+C(n+1,2)^r (k^*)^n-cosets, where C(a,b) denotes the binomial coefficient a choose b.", "revisions": [ { "version": "v1", "updated": "2004-01-19T15:02:29.000Z" } ], "analyses": { "subjects": [ "11D72" ], "keywords": [ "linear equations", "function field", "multiplicative group", "arbitrary transcendence degree", "fixed non-zero coefficients a1" ], "note": { "typesetting": "LaTeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2004math......1231E" } } }