Abstract
Let (Formula presented.) be a fixed field and let X be a simplicial complex on the vertex set V. The Leray number (Formula presented.) is the minimal d such that for all (Formula presented.) and (Formula presented.), the induced complex (Formula presented.) satisfies (Formula presented.). Leray numbers play a role in formulating and proving topological Helly-type theorems. For two complexes (Formula presented.) on the same vertex set V, define the relative Leray number (Formula presented.) as the minimal d such that (Formula presented.) for all (Formula presented.) and (Formula presented.). In this paper we extend the topological colorful Helly theorem to the relative setting. Our main tool is a spectral sequence for the intersection of complexes indexed by a geometric lattice.
Original language | English |
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Pages (from-to) | 730-737 |
Number of pages | 8 |
Journal | Mathematika |
Volume | 67 |
Issue number | 3 |
DOIs | |
State | Published - Jul 2021 |
Bibliographical note
Publisher Copyright:© 2021 The Authors. The publishing rights for this article are licensed to University College London under an exclusive licence.
Keywords
- 52A35
- 55U10