%0 Journal Article %T A note on optimal probability lower bounds for centered random variables %A Mark Veraar %J Mathematics %D 2008 %I arXiv %X In this note we obtain lower bounds for $\P(\xi\geq 0)$ and $\P(\xi>0)$ under assumptions on the moments of a centered random variable $\xi$. The obtained estimates are shown to be optimal and improve results from the literature. The results are applied to obtain probability lower bounds for second order Rademacher chaos. %U http://arxiv.org/abs/0803.0727v2