{ "id": "math/0312407", "version": "v1", "published": "2003-12-22T12:42:44.000Z", "updated": "2003-12-22T12:42:44.000Z", "title": "An uncertainty inequality for finite abelian groups", "authors": [ "Roy Meshulam" ], "comment": "7 pages, no figures", "categories": [ "math.CO" ], "abstract": "Let G be a finite abelian group of order n. For a complex valued function f on G, let \\fht denote the Fourier transform of f. The uncertainty inequality asserts that if f \\neq 0 then |supp(f)| |supp(\\fht)| \\geq n. Answering a question of Terence Tao, the following improvement of the classical inequality is shown: Let d_1