%0 Journal Article %A Durand-Cartagena, Estibalitz %A Jaramillo Aguado, Jesús Ángel %A Shanmugalingam, Nageswari %T Connections between ∞-Poincaré inequality, quasi-convexity, and N1,∞ %D 2009 %U https://hdl.handle.net/20.500.14352/44466 %X We study a geometric characterization of ∞−Poincaré inequality. We show that a path-connected complete doubling metric measure space supports an ∞−Poincaré inequality if and only if it is thick quasi-convex. We also prove that these two equivalent properties are also equivalent to the purely analytic property that N1,∞(X) = LIP∞(X), where LIP∞(X) is the collection of bounded Lipschitz functions on X and N1,∞(X) is the Newton-Sobolev space studied in [DJ]. %~