Rademacher Type and Enflo Type Revisited

Abstract

We establish a dimension-free vector-valued Poincaré-type inequality on the discrete cube for Banach spaces with Rademacher type $p$, $1\le p\le 2$. As a consequence, we obtain $$T_p^R(X)\le T_p^E(X)\le p{T}_p^R(X).$$ This gives an alternative proof that Rademacher type and Enflo type coincide, while improving the constant $\pi /\sqrt{2}$ in the quantitative estimate of Ivanisvili, van Handel, and Volberg \cite{IVV} to $p$.