Exotic operators on the Hardy spaces of the infinite-dimensional torus

Abstract

We quantify the failure of interpolation between Hardy spaces $H^p(\mathbb T^\infty)$ on the infinite-dimensional torus. For any set $A\subseteq[1,\infty]$ such that $A\setminus\{\infty\}$ is closed in $[1,\infty)$, we show that there exists an operator that is densely defined on $H^p(\mathbb T^\infty)$ for all $1\leq p<\infty$ and weak-$\ast$ densely defined on $H^\infty(\mathbb T^\infty)$ that extends to a bounded linear operator on $H^p(\mathbb T^\infty)$ if and only if $p\in A$.