%0 Journal Article %A Assaf Naor %T Discrete Riesz transforms and sharp metric $X_p$ inequalities %J Annals of mathematics %D 2016 %P 991-1016 %V 184 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/articles/10.4007/annals.2016.184.3.9/ %R 10.4007/annals.2016.184.3.9 %G en %F 10_4007_annals_2016_184_3_9