The Godbillon-Vey Invariant in 𝐾𝐾-theory with Real coefficients
By Sara Azzali
Propriétés de relèvement pour les 𝐶^∗-algèbres : du local au global ?
By Gilles Pisier
By Zhendong Xu
Appears in collection : Arbre de Noël du GDR « Géométrie non-commutative »
We solve a question asked by Xu about the order of optimal constants in the Littlewood-Paley-Stein inequality. This relies on a construction of a special diffusion semi-group associated with a martingale which relates the Littlewood G-function with the martingale square function pointwise. This can also be done in vector-valued and noncommutative cases.