On the optimal multilinear Bohnenblust--Hille constants

Abstract

The upper estimates for the optimal constants of the multilinear Bohnenblust--Hille inequality obtained in [J. Funct. Anal. 264 (2013), 429--463] are here improved to: {0.1cm} {enumerate} For real scalars: $K_n\le \sqrt{2}(n-1{)}^{0.526322}$. For complex scalars: $K_n\le \frac{2}{\sqrt{\pi }}(n-1{)}^{0.304975}$.{enumerate} {0.1cm} \noindent We also obtain sharper estimates for higher values of $n$. For instance, \[ K_{n}<1.30379(n-1) ^{0.526322}\] for real scalars and $n>2^8$ and \[ K_{n}<0.99137(n-1) ^{0.304975}\] for complex scalars and $n>2^{15}.$