Maximal estimates for nonsymmetric semigroups
Volume 109 / 1994
Studia Mathematica 109 (1994), 41-49
DOI: 10.4064/sm-109-1-41-49
Abstract
Let $X_0, X_1,..., X_k$ be left-invariant vector fields on a Lie group and let $L = ∑_{i=1}^k X_i^2 + X_0$. Then L is the infinitesimal generator of a semigroup ${p_t}_{t≥0}$ of probability measures on G. Let $P*f(x) = ∑_{0
