Seminários de Álgebra
Collin Bleak (University of St. Andrews)
02/12/2014 Terça-feira, 2 de Dezembro de 2014, 15h30, Sala A2-25 
Instituto para a Investigação Interdisciplinar da Universidade de Lisboa
On Unexpectedly Familiar Groups
For natural n we study a family of groups V_n(G) which are groups of homeomorphisms of the standard n-ary Cantor space C_n, and where each such group naturally contains the Higman-Thompson group V_n as a subgroup. As in many studies of large groups of homeomorphisms, the analysis of V_n(G) depends on Rubin's Theorem and on the local groups of germs induced by the action of V_n(G) on C_n. While it was expected that V_n(G) and V_n would in fact be very distinct groups for any non-trivial value of the parameter G, we instead show that for many possible G we have V_n(G) is actually isomorphic with V_n. We determine exactly when this happens. Joint with Casey Donoven and Julius Jonusas.
FCT - Fundação para a Ciência e a Tecnologia