OpenAI claim summary for Math-2269
mathematicsTop Open Problemscontributionliterature_reportClaim: literature report
Summary of a claim published in openai/math; not a claim by this platform.
The selected theorem concerns the discrete sequence target $\ell_1$ and gives a universal Lipschitz extension bound for maps from Hilbert-space subsets into that target. The recorded question asks for an arbitrary $L^1$ target, including the nonatomic space. No reduction of that target to $\ell_1$ is supplied. Thus the discrete-target extension result is a genuine restricted case, and the larger extension problem remains partial.
Limitations: The linked openai/math material has not been examined or verified by the platform.
Manuscript
Contents
Lipschitz extension from Hilbert spaces into L1
OpenAI's claim
OpenAI presents the following claims relevant to this question, with manuscript numbers following paper order in Sources. In manuscript 1 (family 332; 2026-10-05), the asserted result is that real $\ell_1$ has metric Markov cotype two, giving uniformly controlled Lipschitz extension from Hilbert-space subsets to this target.Mathematical statement of the claimed result
Manuscript 1.
For every finite reversible stochastic matrix $A=(a_{ij})$ with stationary distribution $\pi$, every integer $t\ge1$ and every $x_1,\ldots,x_n\in\ell_1(\mathbb R)$, the claim supplies $y_1,\ldots,y_n$ satisfying \[ \sum_i\pi_i\|x_i-y_i\|_1^2+t\sum_{i,j}\pi_i a_{ij}\|y_i-y_j\|_1^2 \le3024\sum_{i,j}\pi_i\left(\frac1t\sum_{s=1}^tA^s\right)_{ij}\|x_i-x_j\|_1^2. \] Thus the metric Markov cotype-two constant is at most $12\sqrt{21}$. The asserted extension consequence is one universal $K<\infty$ such that every Lipschitz $f:S\to\ell_1$ from a subset of any real Hilbert space $\mathcal H$ extends to $F:\mathcal H\to\ell_1$ with $\operatorname{Lip}(F)\le K\operatorname{Lip}(f)$.Outline of the argument
For manuscript 1 (family 332; 2026-10-05), finite cut representations reconstruct an expected coordinatewise median of three stopped-walk endpoints. A flat-map martingale and quartic potential control the geometric endpoint costs, which a metric comparison converts to the Cesàro energy needed for cotype.Formal verification
No Lean formalization is listed at this snapshot for manuscript 1 (family 332; 2026-10-05).This site has not executed the Lean code. Described statement coverage is not an independent proof check.
Status caveat
The manuscripts were produced by an internal OpenAI model. OpenAI cautions that results without formalization can contain mistakes. This site has not independently checked the proofs; the label records the scope of OpenAI's claim.Sources
- OpenAI, Metric Markov Cotype Two of $\ell$${}_{1}$, 2026-10-05; citation key
OAI:Metric-Markov-Cotype-Two-of-l1-October-5-2026. PDF (GitHub); PDF (direct); Manuscript page and citation; Latest version; Statement source: cor:extension. - OpenAI catalogue entry.