Abstract
Let G be a permutation group on a finite set Ω. A base for G is a subset B ⊆ Ω with pointwise stabilizer in G that is trivial; we write b(G) for the smallest size of a base for G. In this paper we prove that b(G) ≤ 6 if G is an almost simple group of exceptional Lie type and Ω is a primitive faithful G-set. An important consequence of this result, when combined with other recent work, is that b(G) ≤ 7 for any almost simple group G in a non-standard action, proving a conjecture of Cameron. The proof is probabilistic and uses bounds on fixed point ratios.
| Original language | English |
|---|---|
| Pages (from-to) | 116-162 |
| Number of pages | 47 |
| Journal | Proceedings of the London Mathematical Society |
| Volume | 98 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 2009 |
Bibliographical note
Funding Information:The first author acknowledges the support of a Junior Research Fellowship from St John’s College, Oxford, and a Lady Davis Fellowship from The Hebrew University of Jerusalem.
Fingerprint
Dive into the research topics of 'Base sizes for simple groups and a conjecture of Cameron'. Together they form a unique fingerprint.Cite this
- APA
- Author
- BIBTEX
- Harvard
- Standard
- RIS
- Vancouver