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2206.06921

Attainable forms of Assouad spectra

Alex Rutar

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

Audit review

The PDF proves a full classification of attainable Assouad spectra (Theorem A) with the equivalence (a)⇔(b)⇔(c), via: (a)⇒(b) by a standard two-scale covering inequality (Proposition 3.1), (c)⇒(b) by verifying the cap family Cd satisfies the same inequality (Proposition 3.6), (closure under suprema, Proposition 3.7), and (b)⇒(a) by constructing homogeneous Moran sets (Proposition 3.3, Theorem 3.5) and a canonical sup-of-caps representation (Theorem 3.11). The candidate solution follows the same overall structure: two-scale covering for (a)⇒(b), a sup-of-caps functional description for (b)⇒(c), and a Moran-type construction and sup closure for (c)⇒(a). Minor gaps remain in the candidate’s Step 2 (the cap selection/touching argument is asserted rather than established, whereas the paper provides a precise c(κ,λ,y) parametrization and lemmas ensuring global domination), but the approach and main claims match the paper’s results.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

This classification settles a natural and central question about Assouad spectra. The architecture of the proof is elegant and robust, combining sharp covering inequalities, a flexible Moran-set realization scheme, and a canonical sup-of-caps representation. The exposition is generally clear; however, the heart of the (b)⇒(c) direction (choice and control of the cap parameters) is technically dense and could be expanded for readability.