Estimates for trilinear and quadrilinear character sums
Estimates for trilinear and quadrilinear character sums
We obtain new bounds on some trilinear and quadrilinear character sums, which are non-trivial starting from very short ranges of the variables. An application to a modular analogue of a multiplicative hybrid problem of Iwaniec and S\'ark\"ozy (1987) is given. Moreover, we show that for all large primes $p$, there …