Veja como foi o nosso Colóquio, realizado no dia 15 de abril de 2026, com a participação da Françoise Dal'Bo  (Université Rennes, França e French-Uruguayan CNRS-Laboratory IFUMI, Uruguay), que ministrou a palestra intitulada “From linear actions of 2x2 matrices to a flow”.

Abstract: Let G be a discrete subgroup of Sl(2,R) acting on the vectorial plane R^2. Is it possible to describe the closures of the G-orbits? the G-invariant measures? We will bring answers to these questions under conditions on G, using a reformulation in terms of the dynamics of a flow on a hyperbolic surface. If time allows, we will show, using this dynamical point of view, the existence of a group G giving rise to a very surprising G-orbit and an "exotic" G-invariant measure. (Joint work with J.Farre, O.Landesberg, Y.Minsky)