• Groups with Spanier-Whitehead Duality 

      [OWP-2019-23] Nishikawa, Shintaro; Proietti, Valerio (Mathematisches Forschungsinstitut Oberwolfach, 2019-09-17)
      We introduce the notion of Spanier-Whitehead $K$-duality for a discrete group $G$, defined as duality in the KK-category between two $C*$-algebras which are naturally attached to the group, namely the reduced group ...
    • Homology and $K$-Theory of Torsion-Free Ample Groupoids and Smale Spaces 

      [OWP-2020-20] Proietti, Valerio; Yamashita, Makoto (Mathematisches Forschungsinstitut Oberwolfach, 2020-10-09)
      Given an ample groupoid, we construct a spectral sequence with groupoid homology with integer coefficients on the second sheet, converging to the $K$-groups of the groupoid C*-algebra when the groupoid has torsion-free ...