An uncertainty inequality for finite abelian groups

  • Authors:
  • Roy Meshulam

  • Affiliations:
  • Department of Mathematics, Technion, Haifa, Israel

  • Venue:
  • European Journal of Combinatorics
  • Year:
  • 2006

Quantified Score

Hi-index 0.00

Visualization

Abstract

Let G be a finite abelian group of order n. For a complex valued function f on G let fdenote the Fourier transform of f. The classical uncertainty inequality asserts that if f ≠ 0 then |supp(f)| ċ |supp(f)| ≥ |G|. (1) Answering a question of Terence Tao, the following improvement of (1) is shown: Theorem. Let d1 d2 be two consecutive divisors of n. If d1 ≤ k = |supp(f)| ≤ d2 then |supp(f)| ≥ n/d1d2(d1 + d2 - k).