We consider the graph 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 obtained from 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 has precisely t connected components. Moreover, we study the graph, 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 obtained removing the isolated vertices is connected and has diameter at most 3.
The virtually generating graph of a profinite group
Lucchini A.
2021
Abstract
We consider the graph 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 obtained from 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 has precisely t connected components. Moreover, we study the graph, 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 obtained removing the isolated vertices is connected and has diameter at most 3.Pubblicazioni consigliate
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