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2409.08768

Measure-Theoretic Time-Delay Embedding

Jonah Botvinick-Greenhouse, Maria Oprea, Romit Maulik, Yunan Yang

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

Audit review

The paper’s main claim (Theorem 4 and Corollary 1) — that if f: M→N is an embedding then the pushforward F=f#: P2(M)→P2(N) is an embedding, and hence generically Ψh,ϕτ is an embedding when Φh,ϕτ is — is essentially correct. However, the proof of the derivative’s injectivity picks ς=φ∘f−1 as a Cc∞(N) test function even though φ∘f−1 is only defined on f(M); an explicit smooth extension to N (e.g., via a tubular neighborhood and retraction) is not provided in the main text, and the justification offered (that ς∈C1(N) because φ and f are C1) is insufficient as written . The model’s solution provides that missing step cleanly. Apart from this fixable gap and some imprecision about “invertible” (meant: invertible onto its image) in Theorem 3, the paper’s structure aligns with standard OT/AGS theory and Takens, and the core result stands .

Referee report (LaTeX)

\textbf{Recommendation:} minor revisions

\textbf{Journal Tier:} strong field

\textbf{Justification:}

A conceptually natural and technically competent lifting of Takens’ embedding to the Wasserstein space, with applications that illustrate the utility of the measure-theoretic viewpoint. The main results are correct in substance. A small but concrete proof gap (the smooth extension of test functions from f(M) to N in the derivative-injectivity step) needs fixing; wording around invertibility should also be clarified. These are straightforward revisions.