On the existence of a Gysin morphism for the Blow-up of an ordinary singularity

Abstract

In this paper we characterize the Blowing-up maps of ordinary singularities for which there exists a natural Gysin morphism, i.e. a bivariant class $\theta \in Ho{m}_{D(Y)}(R{\pi }_{\ast }{\mathbb{Q}}_X,{\mathbb{Q}}_Y)$, compatible with pullback and with restriction to the complement of the singularity.

arXiv commentTo the memory of Alexandru (Sacha) T. Lascu. Some new results added