Quadratic forms arising from geometry

Algebraic Geometry and Number Theory Seminar

The cup product on topological manifolds or the intersection product on algebraic varieties induce quadratic forms which turn out to be a fine invariant of these geometric objects. We will discuss some old theorems on the signature of these quadratic forms and some applications both of geometric and arithmetic origins. Finally we will study an old conjecture of Grothendieck about those signatures and explain some new evidences.