Lück W., Reich, H. and Schick, T.: Novikov-Shubin invariants for arbitrary group actions and their positivity

• Autors: Wolfgang Lück, Holger Reich, and Thomas Schick
• Titel: Novikov-Shubin invariants for arbitrary group actions and their positivity
• Tel Aviv Topology Conference: Rothenberg Festschrift (1998), 159--176, Contemp. Math., 231, AMS (1999)
• Abstract: We extend the notion of Novikov-Shubin invariant for free G-CW-complexes of finite type to spaces with arbitrary G-actions and prove some statements about their positivity. In particular we apply this to classifying spaces of discrete groups.