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
- arXiv Links
- Abstract ↗PDF ↗
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.