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2409.08061

Khintchine dichotomy for self-similar measures

Timothée Bénard, Weikun He, Han Zhang

correctmedium confidence
Category
math.DS
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:56 AM

Audit review

The paper proves Theorem A (the full Khintchine dichotomy for all self‑similar measures on R) by establishing an effective equidistribution statement (Theorem B, with polynomial rate t^{-c}) and then deriving both the convergence and divergence cases via a refined adaptation of the Khalil–Luethi mechanism in Section 6, including new correlation estimates (e.g., Proposition 6.6) and short-range quasi-independence (Proposition 6.7) . The candidate solution follows the same overall strategy (Dani correspondence → equidistribution along horocycles → Khalil–Luethi implication) and correctly identifies that Theorem B feeds into Theorem A via Khalil–Luethi, noting that Section 6 handles the needed adaptations beyond contractive/open-set assumptions . However, it misstates the rate in Theorem B as exponential e^{-κt} (the paper proves a polynomial rate t^{-c}) and informally invokes “summable in t” error terms; the paper instead obtains the necessary estimates via correlation decay and quasi-independence. After correcting these technical points, the model’s proof aligns with the paper’s approach and conclusions.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

This work proves the full Khintchine dichotomy for all self-similar measures on the real line, overcoming long-standing obstacles (notably for the middle-thirds Cantor measure). It combines new effective equidistribution-in-law for fractal averages with a careful adaptation of the Khalil–Luethi framework, including correlation decay and short-range quasi-independence. The arguments are sound and the contribution is significant. Minor clarifications regarding decay rates and terminology would further enhance clarity.