AN ELEMENTARY APPROACH TO CHARACTER SUMS OVER MULTIPLICATIVE SUBGROUPS

摘要

Let p be an odd prime. Using I. M. Vinogradov’s bilinear estimate, we present an elementary approach to estimate character sums X x2H (x + a), a 2 F? p, where H is a multiplicative subgroup in the finite prime field Fp. Two interesting mean-value estimates are also provided.