Result: SOME REMARKS ON THE PROBABILITY OF GENERATING AN ALMOST SIMPLE GROUP: Some remarks on the probability of generating an almost simple group.
0017-0895
https://boa.unimib.it/handle/10281/2779
https://www.openaccessrepository.it/record/149968
https://hdl.handle.net/11577/127391
https://doi.org/10.1017/S0017089503001241
Further Information
We identify a finite nonabelian simple group \(S\) with the subgroup of inner automorphisms of \(S\) in \(\Aut(S)\). Let \(P(S)\) denote the probability that two randomly chosen elements from \(\Aut(S)\) generate a subgroup containing \(S\), and \(P_S(t)\) be the probability that \(t\) randomly chosen elements from \(S\) generate \(S\). The main result of this paper is that if \(S=\text{PSL}(2,p)\) (where \(p\geq 5\) is a prime), then \(P(S)=P_S(2)+x/|S|\) where \(x\) takes one of four explicit nonnegative values depending on the value of \(p\) modulo \(40\). The proof depends on calculations using \textit{Ph. Hall}'s theorem [Q. J. Math., Oxf. Ser. 7, 134-151 (1936; Zbl 0014.10402)]. Some of these calculations are extended to other finite simple groups using the computer system GAP and give rise to several open questions.