Back to search
2407.01806

Strong primeness for equivalence relations arising from Zariski dense subgroups

Daniel Drimbe, Cyril Houdayer

correctmedium confidence
Category
Not specified
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper states and proves that for Zariski dense subgroups of k-isotropic almost k-simple algebraic groups over local fields of characteristic 0, the orbit equivalence relation R(Γ ↷ X) is strongly prime, giving a direct, non-inductive argument that culminates in Theorem A and its proof completion (thereby establishing the embedding dichotomy) . By contrast, the candidate solution assumes as an input the very strong primeness property it aims to establish (Step 3), and then uses it to conclude strong primeness via a product-intertwining step—this is circular. Although the model references product-intertwining ideas attributed to Spaas, the paper’s proof of Theorem A does not require assuming strong primeness; it derives it directly using algebraic representations and Popa–Ioana intertwining for equivalence relations .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The manuscript delivers a robust and elegant proof of strong primeness for orbit equivalence relations arising from Zariski dense subgroups, extending Zimmer’s classical primeness result and enabling uniqueness-of-factorization consequences. The framework is technically sophisticated yet coherent, combining algebraic representations and Popa–Ioana intertwining. Minor clarifications would further improve accessibility, but the core contributions are solid and significant.