Math-15075 · mathematics · Probability

Math-15075

High-Dimensional Volumes of Random Simplices

Status Partially solved · unsolvedmath.comLLM status Open unverified

Top Open Problems Not reported cataloguedPartially solvedOpen

Statement

Definitions and mathematical statement

The supplied record asks for high-dimensional asymptotics of expected random-simplex volumes. Its sampling law, dimension convention, body scaling, and normalization are not specified, so it does not determine a unique sequence of expectations.

A parameterized formulation makes these missing data explicit. For each positive integer $d$, let $m_d\geq 1$ be an ambient dimension, let $K_d\subset{\mathbb{R}}^{m_d}$ be a compact convex set with nonempty interior, and let $\mu_d$ be a Borel probability measure on $K_d^{m_d+1}$. Let $(X_{d,0},\ldots,X_{d,m_d})$ have joint law $\mu_d$, and define \[ S_d=\operatorname{conv}\{X_{d,0},\ldots,X_{d,m_d}\},\qquad V_d=\operatorname{vol}_{m_d}(S_d), \] where $\operatorname{vol}_{m_d}$ is $m_d$-dimensional Lebesgue measure; this volume is zero when the vertices are affinely dependent. The expected volume is \[ A_d(K_d,\mu_d)={\mathbb{E}}[V_d] =\int_{K_d^{m_d+1}} \operatorname{vol}_{m_d}\!\left(\operatorname{conv}\{x_0,\ldots,x_{m_d}\}\right) \,{\,\mathrm{d}}\mu_d(x_0,\ldots,x_{m_d}). \] This framework does not assume that the vertices are independent or uniformly distributed: neither assumption is supplied by the record.

The requested task is to determine the asymptotic behavior of these expected volumes as $d\to\infty$ for the intended sequences of regular simplices, cubes, and other standard convex bodies, together with the intended normalized asymptotic quantities. The supplied literature assessment also explicitly mentions cross-polytopes. This is a formulation template requiring specification of $m_d$, $K_d$, $\mu_d$, and the normalization before a precise asymptotic target can be stated.

In particular, the source calls the random object a "$(d+1)$-simplex." In the usual dimensional terminology this has dimension $d+1$ and has $d+2$ vertices. A convex hull of $d+1$ points is instead at most $d$-dimensional. The record does not specify the ambient dimension or resolve whether its wording refers to dimension or to the number of sampled vertices. No identification of $m_d$ with $d$ or $d+1$ is therefore imposed. The scale of each containing body and the meaning of "normalized quantities" also remain unresolved.

Short English statement

Determine the high-dimensional asymptotics of the expected volume of a random simplex in a regular simplex, a cube, and other intended standard convex bodies, including the requested normalized quantities. The record leaves the dimension convention, vertex distribution, body scaling, and normalization unspecified; these must be resolved for a unique mathematical problem. Its supplied status is partially solved, which is a dated curation label rather than an independently verified conclusion.

Sources

  • Supplied local registry record: permanent UnsolvedMath ID $30003398$, source problem code catalogue entry, title High-Dimensional Volumes of Random Simplices, in Oberwolfach Reports Open Problems. The record gives proposed year 2017 and names no proposer.
  • Supplied source citation: Mini-Workshop: Perspectives in High-Dimensional Probability and Convexity (2018), Oberwolfach Reports, pp. 499--526, DOI 10.4171/owr/2017/10. Supplied link: https://doi.org/10.4171/owr/2017/10. The background attributes the problem to workshop open-problem discussions documented in Oberwolfach Reports.
  • Supplied literature source, labeled "Oberwolfach report": https://ems.press/content/serial-article-files/46672.
  • Supplied literature source, labeled "Alonso-Gutiérrez et al.": https://arxiv.org/abs/1906.02471. The record supplies no further bibliographic details for this reference.
  • Literature assessment dated exactly 2026-08-21: the supplied curation labels the problem partially solved and states that high-dimensional central-limit results and moment formulas cover important random-simplex models, while the requested asymptotics for the regular simplex, cube, and cross-polytope are not all known in the stated form. This is supplied dated curation derived from the OWR record, not an independently verified literature assessment; the source itself requests independent verification of time-sensitive status and cited claims.
  • The registry supplies the statement-status label corrected_verified and reports a manual semantic, typographic, and LaTeX review claiming self-containment and preservation of the target. That supplied review does not resolve the formulation gaps identified here. No linked source was visited or independently checked for this draft.

Catalogue entry

Statement licence: CC-BY-SA-4.0 · Source file

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