On Lipschitz spaces in the Dunkl setting -- semigroup approach

Abstract

Let $\{P_t\}_{t>0}$ be the Dunkl-Poisson semigroup associated with a root system $R\subset \mathbb R^N$ and a multiplicity function $k\geq 0$. Analogously to the classical theory, we say that a bounded measurable function $f$ defined on $\mathbb R^N$ belongs to the inhomogeneous Lipschitz space $\Lambda_k^\beta$, $\beta>0$, if $$\sup_{t>0} t^{m-\beta} \Big\|\frac{d^m}{dt^m} P_tf\Big\|_{L^\infty}<\infty,$$ where $m=[\beta]+1$. We prove that the spaces $\Lambda^\beta_k$ coincide with the classical Lipschitz spaces.