Potential Wadge Classes

Download or read book Potential Wadge Classes written by Dominique Lecomte and published by American Mathematical Soc.. This book was released on 2013-01-25 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt: Let $\bf\Gamma$ be a Borel class, or a Wadge class of Borel sets, and $2\!\leq\! d\!\leq\!\omega$ be a cardinal. A Borel subset $B$ of ${\mathbb R}^d$ is potentially in $\bf\Gamma$ if there is a finer Polish topology on $\mathbb R$ such that $B$ is in $\bf\Gamma$ when ${\mathbb R}^d$ is equipped with the new product topology. The author provides a way to recognize the sets potentially in $\bf\Gamma$ and applies this to the classes of graphs (oriented or not), quasi-orders and partial orders.