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2009.00182

LARGE INTERSECTION CLASSES FOR POINTWISE EMERGENCE

Yushi Nakano, Agnieszka Zelerowicz

correctmedium confidence
Category
math.DS
Journal tier
Strong Field
Processed
Sep 28, 2025, 12:55 AM

Audit review

The paper proves that, for a mixing subshift of finite type X endowed with the standard cylinder metric dX(x,y)=∑|xj−yj|/β^j, the set E of points with high (super-polynomial) pointwise emergence has full Pesin–Pitskel entropy, full Hausdorff dimension, and full topological pressure for every Hölder potential (Theorem 1.1). This is done via a general Carathéodory (C-)structure and large intersection classes, together with a second, constructive proof in the appendix. The statement and its hypotheses are clear and the arguments are coherent, with the core ingredients spelled out: definition of Ex(ε) and E, the C-structure and G^t(X) classes, a key uniform estimate for saturated sets E(μ), and a simplex-complexity argument ensuring super-polynomial covering numbers in the Wasserstein-1 metric for sets of limit measures (Proposition 3.6), culminating in Theorem 3.7 implying Theorem 1.1 for entropy, Hausdorff dimension, and pressure on subshifts (citing [3] for the (C5) hypothesis) . By contrast, the model’s Phase-2 solution attempts a different saturation approach: it constructs a connected compact set K of invariant measures using an infinite convex superposition of just two fixed invariant measures with weights αn≈1/n^2, and then invokes saturated-set formulas (Pfister–Sullivan for entropy; Zhao–Chen for pressure). The crucial claim that this K has super-polynomial covering numbers in W1 is incorrect: because later coordinates can cancel earlier ones, the “first differing index” argument fails unless the coefficients are strongly lacunary; in fact the set constructed lies in a 1-dimensional affine line segment in the space of measures, so its covering numbers grow only polynomially (degree 1). This invalidates the step G_K⊂E and breaks the lower bound P_E(φ)≥P_X(φ) the model seeks to derive from such G_K. Therefore, while the paper’s theorem and proofs are correct, the model’s proposed proof contains a substantive flaw in its core geometric construction of K.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The manuscript establishes that points with high pointwise emergence form a set of full entropy, full Hausdorff dimension, and full topological pressure for Hölder potentials in mixing SFTs. It advances the large-intersection framework to general Carathéodory dimensions and supplies an alternative constructive proof. The results are meaningful to the thermodynamic formalism of non-typical sets. A few clarifications and minor edits would further improve readability and precision.