1,889 research outputs found
Self-Automaton Semigroups
After reviewing automaton semigroups, we introduce Cayley Automata and the
corresponding Cayley Automaton semigroups. We investigate which semigroups are
isomorphic to their Cayley Automaton semigroup and give some results for
special classes of semigroups. We answer a question posed by Cain relating to
the dual construction.Comment: 18 page
The Spectra of Lamplighter Groups and Cayley Machines
We calculate the spectra and spectral measures associated to random walks on
restricted wreath products of finite groups with the infinite cyclic group, by
calculating the Kesten-von Neumann-Serre spectral measures for the random walks
on Schreier graphs of certain groups generated by automata. This generalises
the work of Grigorchuk and Zuk on the lamplighter group. In the process we
characterise when the usual spectral measure for a group generated by automata
coincides with the Kesten-von Neumann-Serre spectral measure.Comment: 36 pages, improved exposition, main results slightly strengthene
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