English

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

Operator Algebras 2026-01-16 v1 Dynamical Systems Functional Analysis

Abstract

We establish a non-commutative version of the Intermediate Factor Theorem for crossed products associated with product lattices. Given an irreducible lattice Γ<G=G1××Gd\Gamma < G= G_1 \times \dots \times G_d in higher rank semisimple algebraic groups and a trace-preserving irreducible action G(N,τ)G \curvearrowright (\mathcal{N}, \tau), we show that every intermediate von Neumann algebra between NΓ\mathcal{N}\rtimes\Gamma and (L(G/P,νP)N)Γ(L^\infty(G/P,\nu_P)\overline{\otimes}\mathcal{N})\rtimes\Gamma is again a crossed product of the form (L(G/Q,νQ)N)Γ(L^\infty(G/Q,\nu_Q)\overline{\otimes}\mathcal{N})\rtimes\Gamma.

Keywords

Cite

@article{arxiv.2601.09875,
  title  = {Non-commutative Factor theorem for tensor products of lattices in product groups},
  author = {Tattwamasi Amrutam and Yongle Jiang and Shuoxing Zhou},
  journal= {arXiv preprint arXiv:2601.09875},
  year   = {2026}
}

Comments

14 pages; comments are welcome