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Topological automorphisms of modified Sierpiński gaskets realize arbitrary finite permutation groups

✍ Scribed by Reinhard Winkler


Publisher
Elsevier Science
Year
2000
Tongue
English
Weight
71 KB
Volume
101
Category
Article
ISSN
0166-8641

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✦ Synopsis


The n-dimensional Sierpiński gasket X, spanned by n + 1 vertices, has (n + 1)! symmetries acting as the symmetric group on the vertices. The object of this note is the remarkable observation that for n 2 every topological automorphism of X is one of these symmetries. A modification of the arguments yields that, given any finite permutation group G S n+1 acting on an (n + 1)-element set, there is a finite subset T ⊆ X such that G is the group of topological automorphisms of X \ T considered as a group acting faithfully on the vertices.