activity
20232026
collaborators

11 papers

math.OA2026

Invariant von Neumann subalgebras of crossed products and tensor products

Tattwamasi Amrutam, Artem Dudko, Yongle Jiang +1

Let be a countable discrete group acting on a tracial von Neumann algebra in a trace-preserving way. We study invariant von Neumann subalgebras of and of…

math.OA2026

Uniformly recurrent subalgebras in finite von Neumann algebras

Tattwamasi Amrutam, Pierre Fima, Yongle Jiang

We introduce the notion of a uniformly recurrent subalgebra (URA) for a trace-preserving action of a countable discrete group on a finite von Neumann algebra , providing an…

math.OA2026

Factors with prescribed number of invariant subalgebras not arising from subgroups

Yongle Jiang, Qinxuan Xu

For any given integer , we construct i.c.c. groups such that the II factors have exactly -many -invariant von Neumann subalgebras not arising from sub…

math.OA2026

-simplicity, confined subalgebras, and operator algebraic uniform recurrence

Tattwamasi Amrutam, Yongle Jiang

We introduce the notion of confined subalgebras in the context of the group von Neumann algebra. We also define Uniformly Recurrent States -- an operator-algebraic analog of Unifor…

math.OA2026

Non-commutative Factor theorem for tensor products of lattices in product groups

Tattwamasi Amrutam, Yongle Jiang, Shuoxing Zhou

We establish a non-commutative version of the Intermediate Factor Theorem for crossed products associated with product lattices. Given an irreducible lattice $Γ< G= G_1 \times \dot…

math.OA2026

Classification of Invariant Subalgebras in a class of factors with property (T)

Yongle Jiang, Hongyi Li

Let and . We classify all -invariant von Neumann subalgebras in . For , this gives an alternative proof of the…

math.OA2026

On invariant subalgebras when the ISR property fails

Yongle Jiang, Ruoyu Liu

We classify all -invariant von Neumann subalgebras in for . This is the first result on classifying -invariant von Neumann suba…

math.OA2025

Non-commutative Intermediate Factor theorem associated with -dynamics of product groups

Tattwamasi Amrutam, Yongle Jiang, Shuoxing Zhou

Let be a product of two locally compact, second countable groups and be of the form , where $μ_{i} \in \math…

math.OA2025

Invariant -subalgebras of the reduced group -algebra

Tattwamasi Amrutam, Yongle Jiang

Let be a countable discrete group. We say that has -invariant subalgebra rigidity (ISR) property if every -invariant -subalgebra is o…

math.OA2024

Splitting of Tensor Products and Intermediate Factor Theorem: Continuous Version

Tattwamasi Amrutam, Yongle Jiang

Let be a discrete group. Given unital --algebras and , we give an abstract condition under which every -subalgebra of the fo…

math.OA2023

An example of an infinite amenable group with the ISR property

Yongle Jiang, Xiaoyan Zhou

Let be , the finitary permutation (i.e. permutations with finite support) group on positive integers . We prove that has the invariant von Neuma…