Moment estimates for convex measures
arXiv:1207.6618 · doi:10.1214/EJP.v17-2150
Abstract
Let , $\eps >0$, $r\geq (1+\eps) p$, and be a -concave random vector in with Euclidean norm . We prove that $(\E |X|^{p})^{1/{p}}\leq c (C(\eps) \E|X|+σ_{p}(X))$, where $σ_{p}(X)=\sup_{|z|\leq 1}(\E|<z,X>|^{p})^{1/p}$, $C(\eps)$ depends only on $\eps$ and is a universal constant. Moreover, if in addition is centered then $(\E |X|^{-p})^{-1/{p}}\geq c(\eps) (\E|X| - C σ_{p}(X))$.