Extensions of the Colorful Helly Theorem for $d$-collapsible and $d$-Leray complexes
Combinatorics
2023-05-23 v1
Abstract
We present extensions of the Colorful Helly Theorem for -collapsible and -Leray complexes, providing a common generalization to the matroidal versions of the theorem due to Kalai and Meshulam, the ``very colorful" Helly theorem introduced by Arocha, B\'ar\'any, Bracho, Fabila and Montejano, and the ``semi-intersecting" colorful Helly theorem proved by Montejano and Karasev. As an application, we obtain the following extension of Tverberg's Theorem: Let be a finite set of points in with . Then, there exist a partition of and a subset of size , such that for all . That is, we obtain a partition of into parts that remains a Tverberg partition even after removing all but one arbitrary point from .
Keywords
Cite
@article{arxiv.2305.12360,
title = {Extensions of the Colorful Helly Theorem for $d$-collapsible and $d$-Leray complexes},
author = {Minki Kim and Alan Lew},
journal= {arXiv preprint arXiv:2305.12360},
year = {2023}
}
Comments
20 pages, 1 figure