New lower bounds for the constants in the real polynomial Hardy--Littlewood inequality

Abstract

In this short note we obtain new lower bounds for the constants of the real Hardy--Littlewood inequality for $m$-linear forms on $\ell_{p}^{2}$ spaces when $p=2m$ and for certain values of $m$. The real and complex cases for the general case $\ell_{p}^{n}$ were recently investigated by G. Araujo et al. When $n=2$ our results improve the best known estimates for these constants.