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It is well known that every finite simple group has a generating pair. Moreover, Guralnick and Kantor proved that every finite simple group has the stronger property, known as $\frac{3}{2}$-generation, that every nontrivial element is contained in a generating pair. More recently, this result has been generalised in three different directions, which form the basis of this survey article. First, we look at some stronger forms of $\frac{3}{2}$-generation that the finite simple groups satisfy, which are described in terms of spread and uniform domination. Next, we discuss the recent classification of the finite $\frac{3}{2}$-generated groups. Finally, we turn our attention to infinite groups, and we focus on the recent discovery that the finitely presented simple groups of Thompson are also $\frac{3}{2}$-generated, as are many of their generalisations. Throughout the article we pose open questions in this area, and we highlight connections with other areas of group theory.
We consider the graph
$\Gamma _{\text {virt}}(G)$
whose vertices are the elements of a finitely generated profinite group G and where two vertices x and y are adjacent if and only if they topologically generate an open subgroup of G. We investigate the connectivity of the graph
$\Delta _{\text {virt}}(G)$
obtained from
$\Gamma _{\text {virt}}(G)$
by removing its isolated vertices. In particular, we prove that for every positive integer t, there exists a finitely generated prosoluble group G with the property that
$\Delta _{\operatorname {\mathrm {virt}}}(G)$
has precisely t connected components. Moreover, we study the graph
$\widetilde \Gamma _{\operatorname {\mathrm {virt}}}(G)$
, whose vertices are again the elements of G and where two vertices are adjacent if and only if there exists a minimal generating set of G containing them. In this case, we prove that the subgraph
$\widetilde \Delta _{\operatorname {\mathrm {virt}}}(G)$
obtained removing the isolated vertices is connected and has diameter at most 3.
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