activity
20062026
most citedApproximation properties and absence of Cartan subalgebra for free Araki-Woods factors

58 citations · 599 across the 43 of their papers we have counts for

collaborators

45 papers

math.OA2026

The noncommutative topological factor theorem for rank-one product lattices

Cyril Houdayer, Corentin Le Bars

We prove a noncommutative topological factor theorem for irreducible lattices in products of real rank-one simple Lie groups. The intermediate C*-subalgebras between the reduced gr…

math.OA2025

Selfless W-probability spaces and Connes' bicentralizer problem

Cyril Houdayer, Amine Marrakchi

We introduce the notion of selfless W-probability space and study its connection with Connes' bicentralizer problem. In particular, we show that if is a separable type ${\r…

math.OA2024

Operator algebraic characterization of the noncommutative Poisson boundary

Cyril Houdayer

We obtain an operator algebraic characterization of the noncommutative Furstenberg-Poisson boundary associated w…

math.OA2022★ 1 cited

The noncommutative factor theorem for lattices in product groups

Rémi Boutonnet, Cyril Houdayer

We prove a noncommutative Bader-Shalom factor theorem for lattices with dense projections in product groups. As an application of this result and our previous works, we obtain a no…

math.OA2022★ 1 cited

Pointwise inner automorphisms of almost periodic factors

Cyril Houdayer, Yusuke Isono

We prove that a large class of nonamenable almost periodic type factors , including all McDuff factors that tensorially absorb and all free Araki-Woods…

math.OA2021★ 5 cited

Charmenability of higher rank arithmetic groups

Uri Bader, Rémi Boutonnet, Cyril Houdayer

We complete the study of characters on higher rank semisimple lattices initiated in [BH19,BBHP20], the missing case being the case of lattices in higher rank simple algebraic group…

math.OA2021★ 5 cited

Noncommutative ergodic theory of higher rank lattices

Cyril Houdayer

We survey recent results regarding the study of dynamical properties of the space of positive definite functions and characters of higher rank lattices. These results have several…

math.OA2021

Existentially closed W*-probability spaces

Isaac Goldbring, Cyril Houdayer

We study several model-theoretic aspects of W-probability spaces, that is, -finite von Neumann algebras equipped with a faithful normal state. We first study the existential…

math.GR2020★ 26 cited

Charmenability of arithmetic groups of product type

Uri Bader, Rémi Boutonnet, Cyril Houdayer +1

We discuss special properties of the spaces of characters and positive definite functions, as well as their associated dynamics, for arithmetic groups of product type. Axiomatizing…

math.OA2020★ 1 cited

Examples of property (T) II factors with trivial fundamental group

Ionut Chifan, Sayan Das, Cyril Houdayer +1

In this article we provide the first examples of property (T) factors with trivial fundamental group, . Our examples arise as gro…

math.OA2020★ 5 cited

Connes' bicentralizer problem for q-deformed Araki-Woods algebras

Cyril Houdayer, Yusuke Isono

Let be any strongly continuous orthogonal representation of on a real (separable) Hilbert space . For any , we den…

math.GR2019★ 23 cited

Stationary characters on lattices of semisimple Lie groups

Rémi Boutonnet, Cyril Houdayer

We show that stationary characters on irreducible lattices of higher-rank connected semisimple Lie groups are conjugation invariant, that is, they are genuine characters. Th…

math.OA2018★ 5 cited

Structure of extensions of free Araki-Woods factors

Cyril Houdayer, Benjamin Trom

We investigate the structure of crossed product von Neumann algebras arising from Bogoljubov actions of countable groups on Shlyakhtenko's free Araki-Woods factors. Among other res…

math.OA2018★ 9 cited

Structure of bicentralizer algebras and inclusions of type III factors

Hiroshi Ando, Uffe Haagerup, Cyril Houdayer +1

We investigate the structure of the relative bicentralizer algebra for inclusions of von Neumann algebras with normal expectation where is a type ${\r…

math.OA2017★ 4 cited

Factoriality, Connes' type III invariants and fullness of amalgamated free product von Neumann algebras

Cyril Houdayer, Yusuke Isono

We investigate factoriality, Connes' type invariants and fullness of arbitrary amalgamated free product von Neumann algebras using Popa's deformation/rigidity theory. A…

math.DS2017★ 10 cited

Strongly ergodic equivalence relations: spectral gap and type III invariants

Cyril Houdayer, Amine Marrakchi, Peter Verraedt

We obtain a spectral gap characterization of strongly ergodic equivalence relations on standard measure spaces. We use our spectral gap criterion to prove that a large class of ske…

math.OA2017

Singular MASAs in type III factors and Connes' Bicentralizer Property

Cyril Houdayer, Sorin Popa

We show that any type factor with separable predual satisfying Connes' Bicentralizer Property (CBP) has a singular maximal abelian -subalgebra that is the range…

math.GR2016

Locally compact groups acting on trees, the type I conjecture and non-amenable von Neumann algebras

Cyril Houdayer, Sven Raum

We address the problem to characterise closed type I subgroups of the automorphism group of a tree. Even in the well-studied case of Burger-Mozes' universal groups, non-type I crit…

math.OA2016★ 7 cited

Fullness and Connes' invariant of type III tensor product factors

Cyril Houdayer, Amine Marrakchi, Peter Verraedt

We show that the tensor product of any two full factors and (possibly of type ) is full and we compute Connes' invariant $τ(M…

math.OA2016★ 20 cited

Amenable absorption in amalgamated free product von Neumann algebras

Rémi Boutonnet, Cyril Houdayer

We investigate the position of amenable subalgebras in arbitrary amalgamated free product von Neumann algebras . Our main result states that under natural analy…

cs.IT2016

Optimal quantizers for a nonuniform distribution on a Sierpinski carpet

Mrinal Kanti Roychowdhury

The purpose of quantization for a probability distribution is to estimate the probability by a discrete probability with finite support. In this paper, a nonuniform probability mea…

math.OA2016★ 6 cited

Structure of modular invariant subalgebras in free Araki-Woods factors

Rémi Boutonnet, Cyril Houdayer

We show that any amenable von Neumann subalgebra of any free Araki-Woods factor that is globally invariant under the modular automorphism group of the free quasi-free state is nece…

math.OA2015★ 17 cited

Strong solidity of free Araki-Woods factors

Rémi Boutonnet, Cyril Houdayer, Stefaan Vaes

We show that Shlyakhtenko's free Araki-Woods factors are strongly solid, meaning that for any diffuse amenable von Neumann subalgebra that is the range of a normal conditional expe…

math.OA2015★ 15 cited

Bi-exact groups, strongly ergodic actions and group measure space type III factors with no central sequence

Cyril Houdayer, Yusuke Isono

We investigate the asymptotic structure of (possibly type III) crossed product von Neumann algebras arising from arbitrary actions of bi-exa…