Journal article icon

Journal article

Estimating the probability that a given vector is in the convex hull of a random sample

Abstract:
For a d-dimensional random vector X, let pn,X (θ ) be the probability that the convex hull of n independent copies of X contains a given point θ. We provide several sharp inequalities regarding pn,X (θ ) and NX (θ ) denoting the smallest n for which pn,X (θ ) ≥ 1/2. As a main result, we derive the totally general inequality 1/2 ≤ αX (θ )NX (θ ) ≤ 3d + 1, where αX (θ ) (a.k.a. the Tukey depth) is the minimum probability that X is in a fixed closed halfspace containing the point θ. We also show several applications of our general results: one is a moment-based bound on NX (E[X]), which is an important quantity in randomized approaches to cubature construction or measure reduction problem. Another application is the determination of the canonical convex body included in a random convex polytope given by independent copies of X, where our combinatorial approach allows us to generalize existing results in random matrix community significantly.
Publication status:
Published
Peer review status:
Peer reviewed

Actions


Access Document


Files:
Publisher copy:
10.1007/s00440-022-01186-1

Authors


More by this author
Institution:
University of Oxford
Division:
MPLS
Department:
Mathematical Institute
Role:
Author
ORCID:
0000-0003-1176-5837
More by this author
Institution:
University of Oxford
Division:
MPLS
Department:
Mathematical Institute
Oxford college:
St Anne's College
Role:
Author
ORCID:
0000-0002-9972-2809
More by this author
Institution:
University of Oxford
Division:
MPLS
Department:
Mathematical Institute
Role:
Author


Publisher:
Springer
Journal:
Probability Theory and Related Fields More from this journal
Volume:
185
Issue:
3-4
Pages:
705-746
Publication date:
2023-01-07
Acceptance date:
2022-12-21
DOI:
EISSN:
1432-2064
ISSN:
0178-8051


Language:
English
Keywords:
Pubs id:
1318665
Local pid:
pubs:1318665
Deposit date:
2023-01-09

Terms of use



Views and Downloads






If you are the owner of this record, you can report an update to it here: Report update to this record

TO TOP