2204.12207
Shrinking Target Horospherical Equidistribution via Translated Farey Sequences
Jimmy Tseng
correctmedium confidence
- Category
- math.DS
- Journal tier
- Specialist/Solid
- Processed
- Sep 28, 2025, 12:56 AM
- arXiv Links
- Abstract ↗PDF ↗
Audit review
The paper proves the spherical shrinking-target equidistribution (Theorem 1.5) with the precise normalization T^{d-1} and uniformity for T in [T0, e^{η t}] using a renormalization strategy via (translated) Farey sequences and detailed volume/disjointness computations in Sections 4–6; the constant is identified using an exact volume scaling (Theorem 5.10 shows T^{d-1} μ(ST_E) is independent of T) . The candidate's solution outlines a different, standard approach: smoothing the target in G, applying effective mixing/decay of matrix coefficients to horospherical averages, and exploiting the same T^{-(d-1)} scaling, yielding the same limit and uniformity. While the model compresses several technical steps (wavefront control in the cusp, Sobolev norm bounds under smoothing, and an explicit effective equidistribution inequality) into citations, these ingredients are known in the literature and align with the statement of the theorem. The paper’s proof is complete and rigorous via its own machinery, and the model’s proof sketch is correct in outline but would need the stated technical tools to be spelled out for full rigor.
Referee report (LaTeX)
\textbf{Recommendation:} minor revisions \textbf{Journal Tier:} specialist/solid \textbf{Justification:} The manuscript establishes spherical shrinking-target equidistribution with the sharp normalization and a robust uniformity window, using a renormalization method via (translated) Farey sequences and precise volume/disjointness analysis. The extension to generic L via Section 8.5 is clear, and the exact scaling T\^{d-1}μ(ST\_E)=T0\^{d-1}μ(ST0E) is proved cleanly. The exposition could benefit from minor cross-reference polish and a brief high-level comparison with mixing-based proofs, but overall the results are correct and well-presented. The core claims (e.g., Theorem 1.5 and Theorem 5.10) align tightly with the constructed geometry and volume computations.