On Relative Invariant Subalgebra Rigidity Property
Fuente:
arXiv
Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2026
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866917386465050624 |
|---|---|
| author | Amrutam, Tattwamasi |
| author_facet | Amrutam, Tattwamasi |
| contents | A countable discrete group $Γ$ is said to have the relative ISR-property if for every non-trivial normal subgroup $N\trianglelefteqΓ$ and every von Neumann subalgebra $\mathcal{M}\subseteq L(Γ)$ invariant under conjugation by $N$, one has $\mathcal{M}=L(K)$ for some subgroup $K\leΓ$. Similarly, $Γ$ has the relative $C^*$-ISR-property if every $N$-invariant unital $C^*$-subalgebra $\mathcal{A} \subseteq C_r^*(Γ)$ is of the form $C_r^*(K)$. We show that every torsion-free acylindrically hyperbolic group with trivial amenable radical satisfies the relative ISR property. Moreover, we also show that all torsion-free hyperbolic groups have the relative $C^*$-ISR property. Furthermore, we establish an analogous relative ISR-property for irreducible lattices in higher-rank semisimple Lie groups, such as $\mathrm{SL}_d(\mathbb{Z})$ ($d \geq 3$), with trivial center. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2604_04835 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | On Relative Invariant Subalgebra Rigidity Property Amrutam, Tattwamasi Operator Algebras Dynamical Systems Functional Analysis General Topology Geometric Topology A countable discrete group $Γ$ is said to have the relative ISR-property if for every non-trivial normal subgroup $N\trianglelefteqΓ$ and every von Neumann subalgebra $\mathcal{M}\subseteq L(Γ)$ invariant under conjugation by $N$, one has $\mathcal{M}=L(K)$ for some subgroup $K\leΓ$. Similarly, $Γ$ has the relative $C^*$-ISR-property if every $N$-invariant unital $C^*$-subalgebra $\mathcal{A} \subseteq C_r^*(Γ)$ is of the form $C_r^*(K)$. We show that every torsion-free acylindrically hyperbolic group with trivial amenable radical satisfies the relative ISR property. Moreover, we also show that all torsion-free hyperbolic groups have the relative $C^*$-ISR property. Furthermore, we establish an analogous relative ISR-property for irreducible lattices in higher-rank semisimple Lie groups, such as $\mathrm{SL}_d(\mathbb{Z})$ ($d \geq 3$), with trivial center. |
| title | On Relative Invariant Subalgebra Rigidity Property |
| topic | Operator Algebras Dynamical Systems Functional Analysis General Topology Geometric Topology |
| url | https://arxiv.org/abs/2604.04835 |