A. Marrakchi

activity

20172020

collaborators

7 papers

math.GR2020

Isometric actions on Lp-spaces: dependence on the value of p

Amine Marrakchi, Mikael de la Salle

Answering a question by Chatterji--Druţu--Haglund, we prove that, for every locally compact group $G$ , there exists a critical constant $p_{G} \in [0, \infty]$ such that $G$ admits a…

math.OA2019

On the weak relative Dixmier property

Amine Marrakchi

We show that every inclusion of von Neumann algebras with a faithful normal conditional expectation has the weak relative Dixmier property. This answers a question of Popa \cite{Po…

math.OA2019

Tensor product decompositions and rigidity of full factors

Yusuke Isono, Amine Marrakchi

We obtain several rigidity results regarding tensor product decompositions of factors. First, we show that any full factor with separable predual has at most countably many tensor…

math.OA2019

Full factors and co-amenable inclusions

Jon Bannon, Amine Marrakchi, Narutaka Ozawa

We show that if $M$ is a full factor and $N \subset M$ is a co-amenable subfactor with expectation, then $N$ is also full. This answers a question of Popa from 1986. We also genera…

math.OA2018

Full factors, bicentralizer flow and approximately inner automorphisms

Amine Marrakchi

We show that a factor $M$ is full if and only if the $C^{*}$ -algebra generated by its left and right regular representations contains the compact operators. We prove that the bicentr…

math.OA2018

Fullness of crossed products of factors by discrete groups

Amine Marrakchi

Let $M$ be an arbitrary factor and $σ : Γ ↷ M$ an action of a discrete group. In this paper, we study the fullness of the crossed product $M ⋊_{σ} Γ$ . When $Γ$ is a…