Small Gál sums and applications
Résumé
In recent years, maximizing Gál sums regained interest due to a firm link with large values of L-functions. In the present paper, we initiate an investigation of small sums of Gál type, with respect to the L1-norm. We also consider the intertwined question of minimizing weighted versions of the usual multiplicative energy. We apply our estimates to: (i) a logarithmic refinement of Burgess' bound on character sums, improving previous results of Kerr, Shparlinski and Yau; (ii) an improvement on earlier lower bounds by Louboutin and the second author for the number of non vanishing theta functions associated to Dirichlet characters; and (iii) new lower bounds for low moments of character sums.
Domaines
Mathématiques [math]Origine | Fichiers produits par l'(les) auteur(s) |
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