In recent years, maximizing Gál sums regained interest due to a firm link with large values of (Formula presented.) -functions. In the present paper, we initiate an investigation of small sums of Gál type, with respect to the (Formula presented.) -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 nonvanishing theta functions associated to Dirichlet characters; and (iii) new lower bounds for low moments of character sums.
Small Gál sums and applications
Munsch M.;
2021-01-01
Abstract
In recent years, maximizing Gál sums regained interest due to a firm link with large values of (Formula presented.) -functions. In the present paper, we initiate an investigation of small sums of Gál type, with respect to the (Formula presented.) -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 nonvanishing theta functions associated to Dirichlet characters; and (iii) new lower bounds for low moments of character sums.
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
