“Iterated Wreath Products in Product Action, in search for new HJI groups”
Mercoledì 1 Marzo 2023, ore 11:00 - Aula 1BC45 - Matteo Vannacci (Universidad del Pais Vasco - Bilbao)
A just infinite group is an infinite group without infinite proper quotients. A group is said to be hereditarily just infinite (HJI) if all of its finite index subgroups are just infinite. A classical classification theorem of Grigorchuk-Wilson states that a residually finite just infinite group is either: (a) a branch group or (b) an HJI group. Branch groups have been extensively studied (e.g. Grigorchuk group), but HJI groups remain a very mysterious class. In this talk, I will report on some recent work on the search for new HJI subgroups of iterated wreath products in product action.