SoSe 24 Seminar: de Rham cohomology

Time and place: Wednesday 10-12 in M009

Program

The goal of this seminar is to introduce and study de Rham cohomology, which is an invariant of smooth manifolds defined using differential forms. It is related both to analysis (via the fundamental theorem of calculus and Stokes’ theorem) and algebraic topology (as de Rham cohomology turns out to be isomorphic to singular cohomology). Moreover, the ideas underlying the definition of de Rham cohomology are quite versatile and can be applied in many other geometric contexts, for example in algebraic geometry.

The seminar will closely follow Chapter I of the book Differential Forms in Algebraic Topology by R. Bott and L. W. Tu and cover most of the results therein. The main theorem is Poincaré duality, which is a surprising symmetry in the cohomology of smooth compact manifolds. We will discuss it for both oriented and nonorientable manifolds.

Date Speaker Topic
17.04 The de Rham complex of Euclidean space
24.04 The de Rham complex of a smooth manifold
01.05
08.05 The Mayer–Vietoris sequence
15.05 Orientation and integration
22.05 Stokes’ theorem
29.05 The Poincaré lemma
05.06 The Poincaré lemma with compact supports
12.06 Finiteness of de Rham cohomology
19.06 Poincaré duality for oriented manifolds
26.06 The degree of a proper map
03.07 The Künneth formula and the Leray–Hirsch theorem
10.07 The orientation bundle and the twisted de Rham complex
17.07 Densities and Poincaré duality for nonorientable manifolds