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Related papers: Hypercontractivity in group von Neumann algebras

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In this article, we prove Neveu decomposition for the action of the locally compact amenable semigroup of positive contractions on semifinite von Neumann algebras and thus, it entirely resolves the problem for the actions of arbitrary…

Operator Algebras · Mathematics 2023-08-29 Panchugopal Bikram , Diptesh Saha

In this talk, I will survey recent progress made on the classification of von Neumann algebras arising from countable groups and their actions on probability spaces. In particular, I will present the first results which provide classes of…

Operator Algebras · Mathematics 2012-12-04 Adrian Ioana

Let $\mathcal{M}$ be a von Neumann algebra equipped with a faithful semifinite normal weight $\phi$ and $\mathcal{N}$ be a von Neumann subalgebra of $\mathcal{M}$ such that the restriction of $\phi$ to $\mathcal{N}$ is semifinite and such…

Operator Algebras · Mathematics 2016-03-16 Éric Ricard , Quanhua Xu

Using Popa's deformation/rigidity theory, we investigate prime decompositions of von Neumann algebras of the form $L(\mathcal{R})$ for countable probability measure preserving equivalence relations $\mathcal{R}$. We show that…

Operator Algebras · Mathematics 2015-10-30 Daniel J. Hoff

Given a discrete measured groupoid $\mathcal{G}$, we study properties of the corresponding von Neumann algebra $L(\mathcal{G})$ using the techniques of Popa's deformation/rigidity theory. More specifically, we define and study the Gaussian…

Operator Algebras · Mathematics 2025-09-19 Felipe Flores , James Harbour

In the first part of this article we present a growth condition on the potential $q$ in the Schr\"odinger operator $H=-\Delta + q(x)$ in $\mathrm{L}^{2}\left( \mathbb{R}^{n} \right)$ that implies Rosen inequalities for the ground state…

Analysis of PDEs · Mathematics 2026-02-05 Christoph Schwerdt , Alexander Mill , Dirk Hundertmark

Using an approach emerging from the theory of closable derivations on von Neumann algebras, we exhibit a class of groups CR satisfying the following property: given any groups G_1, G_2 in CR, then any free, ergodic, measure preserving…

Operator Algebras · Mathematics 2019-12-19 Ionut Chifan , Jesse Peterson

We show that moment inequalities in a wide variety of economic applications have a particular linear conditional structure. We use this structure to construct uniformly valid confidence sets that remain computationally tractable even in…

Econometrics · Economics 2022-12-20 Isaiah Andrews , Jonathan Roth , Ariel Pakes

An essentially free group action of $\Gamma$ on $(X,\mu)$ is called W*-superrigid if the crossed product von Neumann algebra $L^\infty(X) \rtimes \Gamma$ completely remembers the group $\Gamma$ and its action on $(X,\mu)$. We prove…

Operator Algebras · Mathematics 2023-07-11 Daniel Drimbe , Stefaan Vaes

Finding upper bounds for character ratios is a fundamental problem in asymptotic group theory. Previous bounds in the symmetric group have led to remarkable applications in unexpected domains. The existing approaches predominantly relied on…

Combinatorics · Mathematics 2026-04-02 Noam Lifshitz , Avichai Marmor

We prove stability results in hypercontractivity estimates for the Hopf--Lax semigroup in $\mathbb R^n$ and apply them to deduce stability results for the Euclidean $L^p$-logarithmic Sobolev inequality for any $p>1$. As a main tool, we use…

Analysis of PDEs · Mathematics 2025-09-01 Zoltán M. Balogh , Alexandru Kristály

We introduce an alternative to the notion of `fast rate' in Learning Theory, which coincides with the optimal error rate when the given class happens to be convex and regular in some sense. While it is well known that such a rate cannot…

Statistics Theory · Mathematics 2015-02-26 Shahar Mendelson

We establish pointwise almost everywhere convergence for ergodic averages along polynomial sequences in nilpotent groups of step two of measure-preserving transformations on $\sigma$-finite measure spaces. We also establish corresponding…

Dynamical Systems · Mathematics 2022-09-07 Alexandru D. Ionescu , Ákos Magyar , Mariusz Mirek , Tomasz Z. Szarek

We give an algorithm for solving equations and inequations with rational constraints in virtually free groups. Our algorithm is based on Rips classification of measured band complexes. Using canonical representatives, we deduce an algorithm…

Group Theory · Mathematics 2020-07-20 François Dahmani , Vincent Guirardel

In recent work, we developed a method to construct invertible and non-invertible symmetries of finite-group gauge theories as topological domain walls on the lattice. In the present work, we consider abelian and non-abelian finite-group…

Strongly Correlated Electrons · Physics 2024-12-24 Clay Cordova , Davi B. Costa , Po-Shen Hsin

We study analytic properties of graph product of finite groups with a hyperbolic defining graph. This is done by studying dynamics on the Bowditch compactification of the extension graph, or the crossing graph, of graph product. In…

Group Theory · Mathematics 2024-12-25 Koichi Oyakawa

This paper is devoted to the study of noncommutative ergodic theorems for connected amenable locally compact groups. For a dynamical system $(\mathcal{M},\tau,G,\sigma)$, where $(\mathcal{M},\tau)$ is a von Neumann algebra with a normal…

Operator Algebras · Mathematics 2016-05-13 Mu Sun

We study analogues of classical Hilbert transforms as fourier multipliers on free groups. We prove their complete boundedness on non commutative $L^p$ spaces associated with the free group von Neumann algebras for all $1<p<\infty$. This…

Operator Algebras · Mathematics 2017-10-18 Tao Mei , Eric Ricard

We study the von Neumann algebra, generated by the regular representations of the infinite-dimensional nilpotent group $B_0^{\mathbb Z}$. In [14] a condition have been found on the measure for the right von Neumann algebra to be the…

Operator Algebras · Mathematics 2009-07-28 Ivan Dynov , Alexandre Kosyak

In a separable Hilbert space, we study supercontractivity and ultracontractivity properties for a transition semigroups associated with a stochastic partial differential equations. This is done in terms of exponential integrability of…

Probability · Mathematics 2024-05-30 Luciana Angiuli , Davide A. Bignamini , Simone Ferrari