Collin Bleak (University of St. Andrews)
02/12/2014 Terçafeira, 2 de Dezembro de 2014, 15h30, Sala A225
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 nary Cantor space C_n, and where each such group naturally contains the HigmanThompson 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 nontrivial 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. 
