Cohn's problem on character sums (see , p. 202) asks whether a multiplicative character on a finite field can be characterized by a kind of two level autocorrelation property. Let f be a map from a finite field F to the complex plane such that f (0)=0, f (1)=1, and | f (:)| =1 for all :{0. In this p
On a Character Sum Problem of Cohn
✍ Scribed by Pär Kurlberg
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 92 KB
- Volume
- 92
- Category
- Article
- ISSN
- 0022-314X
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✦ Synopsis
Let f be a complex-valued function on a finite field F such that f(0)=0, f(1)=1, and |f(x)|=1 for x ] 0. H. Cohn asked if it follows that f is a nontrivial multiplicative character provided that ; x ¥ F f(x) f(x+h)=-1 for h ] 0. We prove that this is the case for finite fields of prime cardinality under the assumption that the nonzero values of f are roots of unity.
📜 SIMILAR VOLUMES
We prove some partial results concerning the following problem: Assume that F is a finite field, a i is a complex number for each i # F such that a 0 =0, a 1 =1, |a i | =1 for all i # F "[0], and i # F a i+j aÄ i =&1 for all i # F "[0]. Does it follow that the function i Ä a i is a multiplicative ch