Push-forwards for Witt groups of schemes

Commentarii Mathematici Helvetici, 86, issue 2, 2009, p. 437-468
(1^st online appearance of the preprint on the 3-7-2008)

We define push-forwards for Witt groups of schemes along proper morphisms, using Grothendieck duality theory. This article is an application of results of Tensor-triangulated categories and dualities to triangulated monoidal symmetric closed structures on some derived categories of schemes together with classical derived functors.