Push-forwards for Witt groups of schemes

  • Baptiste Calmès

    Université d'Artois, Lens, France
  • Jens Hornbostel

    Bergische Universität Wuppertal, Germany


Using suitable closed symmetric monoidal structures on derived categories of schemes, as well as adjunctions of the type (Lf,Rf)({\rm L}f^*,{\rm R}f_*) and (Rf,f!)({\rm R}f_*,f^!) (i.e. Grothendieck duality theory), we define push-forwards for coherent Witt groups along proper morphisms between separated noetherian schemes. We also establish fundamental theorems for these push-forwards (e.g. base change and projection formula) and provide some computations.

Cite this article

Baptiste Calmès, Jens Hornbostel, Push-forwards for Witt groups of schemes. Comment. Math. Helv. 86 (2011), no. 2, pp. 437–468

DOI 10.4171/CMH/230