Introduction

Abstract

Sheaf theory has its origin in classical algebraic topology. One of the highlights of algebraic topology is the Poincaré duality isomorphism between the cohomology and homology of a compact oriented manifold. A powerful generalization appeared in the 1960s through the work of Verdier [SHS]. This Poincaré-Verdier duality can only be formulated in the abstract framework of derived and triangulated categories, and is related to the functorial formalism of sheaf theory, what Grothendieck calls the “six operations on sheaves”, i.e. the six functors

$$ {e_\lambda }(x) = {e^{i2\pi }}^{\lambda x},\lambda \in \Lambda $$