On February 14, 2023, Raphael Steiner from ETH Zürich gave a talk at the Discrete Math Seminar on a stronger version of Hadwiger’s conjecture, which finds a clique minor in which one of its branch set is a singleton. The title of his talk was “Strengthening Hadwiger’s conjecture for 4- and 5-chromatic graphs“. He is currently visiting the IBS discrete mathematics group for 2 weeks.