Riesz means on symmetric spaces

Anestis Fotiadis, Effie Papageorgiou

Let $X$ be a non-compact symmetric space of dimension $n$. We prove that if $f\in L^p(X)$, $1\le p\le 2$, then the Riesz means $S_R^z\left(f\right)$ converge to $f$ almost…