Nicola Cavallucci

I will present a finiteness theorem for groups acting on CAT(0) spaces with bounded diameter. The main difficulty consists in understanding the collapsing case, namely when the injectivity radius is small. If there is time I will also discuss the description of all possible Gromov-Hausdorff limits of sequences of uniformly cocompact CAT(0) spaces. The seminar is partially based on joint works with Andrea Sambusetti (University of Rome).