## Optimal mean value estimates beyond Vinogradov's mean value theorem

### Volume 200 / 2021

Acta Arithmetica 200 (2021), 149-182
MSC: 11L15, 11D45, 11L07, 11P55.
DOI: 10.4064/aa200824-9-3
Published online: 20 July 2021

#### Abstract

We establish improved mean value estimates associated with the number of integer solutions of certain systems of diagonal equations, in some instances attaining the sharpest conjectured conclusions. This is the first occasion on which bounds of this quality have been attained for Diophantine systems not of Vinogradov type. As a consequence of this progress, whenever $u \ge 3v$ we obtain the Hasse principle for systems consisting of $v$ cubic and $u$ quadratic diagonal equations in $6v+4u+1$ variables, thus attaining the convexity barrier for this problem.