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arXiv · 1409.2292

On the Covering Number of Small Symmetric Groups and Some Sporadic Simple Groups

Luise-Charlotte Kappe·Daniela Nikolova-Popova·Eric Swartz
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Abstract

A set of proper subgroups is a covering for a group if its union is the whole group. The minimal number of subgroups needed to cover $G$ is called the covering number of $G$, denoted by $\sigma(G)$. Determining $\sigma(G)$ is an open problem for many non-solvable groups. For symmetric groups $S_n$, Mar\'oti determined $\sigma(S_n)$ for odd $n$ with the exception of $n=9$ and gave estimates for $n$ even. In this paper we determine $\sigma(S_n)$ for $n = 8$, $9$, $10$ and $12$. In addition we find the covering number for the Mathieu group $M_{12}$ and improve an estimate given by Holmes for the Janko group $J_1$.

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Luise-Charlotte Kappe, Daniela Nikolova-Popova, Eric Swartz. 2014-09-08. On the Covering Number of Small Symmetric Groups and Some Sporadic Simple Groups. https://arxiv.org/abs/1409.2292

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