• Aucun résultat trouvé

In this exercise sheet, we work out some of the details in the proof of the Poincar´e Duality Theorem

N/A
N/A
Protected

Academic year: 2022

Partager "In this exercise sheet, we work out some of the details in the proof of the Poincar´e Duality Theorem"

Copied!
1
0
0

Texte intégral

(1)

EXERCISES FOR TOPOLOGY III, WS05/06 Sheet 8, December 8th 2005

Solutions due on Thursday, 15th of December.

In this exercise sheet, we work out some of the details in the proof of the Poincar´e Duality Theorem.

Exercise 8.1. Show that if M is R-oriented of dimension n, and if U ⊂ V ⊂ M are open subsets, then the diagram

Hcq(U) D //

i

Hn−q(U)

i

Hcq(V) D //Hn−q(V) is commutative, with i induced by the inclusion U ⊂V. Exercise 8.2. Prove the Poincar´e Duality Theorem for Rn.

Exercise 8.3. Consider an open triad (X, U, V), i.e. X is a space and U and V are open subsets. Construct and prove the exactness of the relative Mayer-Vietoris sequence

−→ Hq(X, U ∩V)→Hq(X, U)⊕Hq(X, V)→Hq(X, U ∪V)−→ Hq−1(X, U ∩V)→ Similarly, prove the existence of the relative Mayer-Vietoris sequence in cohomology

δ−Hq(X, U∩V)←−Hq(X, U)⊕Hq(X, V)←−Hq(X, U∪V)←−δ Hq−1(X, U∩V)←− Exercise 8.4. LetU andV be open subsets ofX, and consider the relative Mayer- Vietoris sequences of the triad (X, U, V), as constructed in the previous exercise.

Show that if a∈Hn+1(X, U ∪V) and if β ∈Hq(X, U ∩V) then the equality

∂(a)∩β =±a∩δ(β) holds in Hn−q(X).

Exercise 8.5. Prove that taking the colimit over a directed set of indices is an exact functor. Find an example where the colimit functor (over a non-directed indexing category) is not exact.

Typeset byAMS-TEX

Références

Documents relatifs

Using, on the one side, a general result in linear algebra due to Klingenberg (see [Kli54]) and on the other side, a theorem on the holonomy of pseudo-Riemannian ma- nifolds

hopes—' Jetzt habe ich gute Hoffnung.' Another hour brought us to a place where the gradient slackened suddenly. The real work was done, and ten minutes further wading through

These results are deduced from several functional inequalities, among them the Nash inequality, the Poincar´ e inequality and the Log-Sobolev inequality.. Let us emphasize that the

The proof is “completely linear” (in the sense that it can not be generalized to a nonlinear equation) and the considered initial data are very confined/localized (in the sense

for the heat equation (that is δ = 0 in (2); there, the authors prove a Liouville Theorem which turns to be the trivial case of the Liouville Theorem proved by Merle and Zaag in

In the cases which were considered in the proof of [1, Proposition 7.6], the case when the monodromy group of a rank 2 stable bundle is the normalizer of a one-dimensional torus

[7] Chunhui Lai, A lower bound for the number of edges in a graph containing no two cycles of the same length, The Electronic J. Yuster, Covering non-uniform hypergraphs

In this note we prove that the essential spectrum of a Schrödinger operator with δ-potential supported on a finite number of compact Lipschitz hypersurfaces is given by [0, +∞)..