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2402.16210

Factor Complexity of the Most Significant Digits of a^{n^d}

Mehdi Golafshan, Ivan Mitrofanov

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

Audit review

The paper proves that for w defined by the most significant decimal digit of 2^{n^d}, the factor complexity p_w(k) is eventually a polynomial of degree d(d+1)/2, via a d-dimensional affine unipotent torus model and a careful hyperplane-arrangement count. The candidate solution claims essentially the same end-result but (i) asserts a torus of dimension D = d(d+1)/2 (confusing the ambient system dimension with the complexity polynomial’s degree), (ii) generalizes to arbitrary base b and multiplicatively independent a without justification, and (iii) glosses over key technical steps (density/equidistribution of the orbit for the proposed system, control of singular intersections) that the paper handles rigorously. Because of the dimension mistake and missing arguments, the model’s solution is not correct as stated, even though its conclusion matches the paper’s theorem in the special case a=2, base 10.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The result is clean and the method is solid: an explicit d-dimensional affine unipotent torus model, density via equidistribution, and a precise Vandermonde-based count with singularity control. The paper is readable and correct, but a few expository enhancements would increase accessibility and reduce the need for the reader to fill in omitted routine steps.