Back to search
2507.04058

Effective Gaps between Singular Values of Non-Stationary Matrix Products Subject to Non-Degenerate Noise

Sam Bednarski, Jonathan Dewitt, Anthony Quas

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

Audit review

The paper proves the ε^2 n lower bounds for singular-value gaps in both expectation and almost surely via a rigorous miniflag/fibered-entropy framework, with explicit additivity and quantitative one-step entropy production, culminating in Theorem 1.1 and Theorem 6.7. By contrast, the model’s outline hinges on unproved uniform Doeblin-type minorization on Grassmannians, a telescoping simple-root cocycle bound with uncontrolled boundary terms, and a uniform second-order perturbation lower bound for α_k that fails at degeneracies; as written, these gaps prevent a complete or correct proof.

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

The work gives a robust, quantitative framework for proving ε\^2 n lower bounds on singular-value gaps for non-stationary products under small absolutely continuous additive noise. The miniflag/fibered-entropy mechanism is elegant and general, offering a clean path to both expectation and almost-sure statements. The paper is well-crafted; a few local clarifications and explicit tracking of constants would further aid readers.