Functional Inequalities for Stable-Like Dirichlet Forms

Let $V\in C^2(\R^d)$ such that $\mu_V(\d x):= \e^{-V(x)}\,\d x$ is a probability measure, and let $\aa\in (0,2)$. Explicit criteria are presented for the $\aa$-stable-like Dirichlet form $$\E_{\aa,V}(f,f):= \int_{\R^d\times\R^d} \ff{|f(x)-f(y)|^2}{|x-y|^{d+\alpha}}\,\d y\,\e^{-V(x)}\,\d x$$ to satisfy Poincar\'e-type (i.e., Poincar\'e, weak Poincar\'e and super Poincar\'e) inequalities. As applications, sharp functional inequalities are derived for the Dirichlet form with $V$ having some typical growths. Finally, the main result of \cite{MRS} on the Poincar\'e inequality is strengthened