Time-resolved ultrafast spectroscopy: general discussion. (13th May 2021) - Ashfold, Michael; Chergui, Majed; Fischer, Ingo; Ge, Lingfeng; Grell, Gilbert; Ivanov, Misha; Kirrander, Adam; Kornilov, Oleg; Krishnan, Sivarama R.; Küpper, Jochen; Kuttner, Christian; Makhija, Varun; et al.