Kloosterman sums with primes to composite moduli
arXiv:1911.09981
Abstract
We obtain a new estimate for Kloosterman sum with primes to composite modulo , that is, for the exponential sum of the type \[ \sum\limits_{p\leqslant X,\;p\,\nmid q}\exp{\biggl(\frac{2πi}{q}\bigl(a\overline{p}+bp\bigr)\,\biggr)},\quad (ab,q)=1,\quad p\overline{p}\equiv 1\pmod{q}, \] which is non-trivial in the case when . We also apply this estimate to the proof of solvability of some congruences with inverse prime residues .
Dedicated to Dmitry Aleksandrovich Popov on the occasion with his 80th anniversary. 23 pages