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2504.06424

The Density Finite Sums Theorem

Bryna Kra, Joel Moreira, Florian K. Richter, Donald Robertson

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

Audit review

The uploaded paper proves the density finite sums theorem up to any fixed length k with a common shift (Theorem 1.1), and reduces the combinatorial statement to a dynamical one (Theorem 1.2), then back via an Erdős-progression-to-finite-sums lemma and a tailored correspondence principle. The key statements and the flow Theorem 1.2 ⇒ Lemma 2.2 ⇒ Theorem 1.1 are explicitly given in the manuscript. The candidate solution outlines exactly this route: Furstenberg correspondence; apply the KMRR dynamical result; then translate back. Minor slips: it attributes the “finite sums hit after a shift” conclusion directly to Theorem 1.2, whereas in the paper this conclusion comes from combining Theorem 1.2 with Lemma 2.2; and it cites a more standard inequality-style correspondence principle rather than the paper’s stronger coding version. These do not affect correctness of the argument. See Theorem 1.1 (density finite sums with shift) and its proof-by-reduction to Theorem 1.2, together with Lemma 2.2 and Theorem 2.3 in the paper .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} top field-leading

\textbf{Justification:}

The manuscript delivers a best-possible density analogue (up to fixed length k with shift) of Hindman’s finite sums phenomenon, using new dynamical ideas (progressive measures) and refined structural tools (pronilfactors, unique ergodicity), and a strengthened correspondence principle. It consolidates and extends recent advances in sumset configurations in sets of positive density. The work is timely, technically deep, and likely to become a reference. Some minor clarifications would further aid readability.