Algebraic Topology
Spring 2009

 

International Master Class

Institute of Mathematics

Vietnam Academy of Science and Technology



 

TIME and PLACE

  • You can find the time-schedule for the course at the Center for Postgarduate Training, Inst. of Math. The first lecture will be held on Wednesday, January 14, 2009.

  • Lecture hall 5, Building A14

INSTRUCTOR

Prof. Nguyen Viet Dung, Institute of Mathematics, VAST

Prof. Lionel Schwartz, Univertsité Paris 13



Contents of the course

Chapter 0: Generalities

1.0

Generalities on categories, functors and natural transformations. The Yoneda lemma. Examples.

2.0

Recollections on general topology : quotient topology, filtration (direct limit topology), the compact open topology on mapping spaces. Connected spaces and arcwise-connected (or path-connected) spaces. Definition of $\pi_0(X)$.

3.0

Actions of topological groups : essentially proper free actions of locally compact groups on locally compact spaces.

4.0

Examples of spaces : the spheres, the classical groups, the grassmanians, (in particular projective spaces) $S^\infty, RP^\infty,  CP^\infty$.

5.0

Graphs, the Euler characteristic of a graph.

6.0

Cell complexes (definition and examples).

Chapter 1: The Fundamental Group

1.1

Definition of based and unbased homtopy. Definition of contractible space (in particular $S^\infty$ is contractible). Definition of a retract, of a deformation retract.

1.2

Definition of the fundamental group $\pi_1(X,x_0)$ as a functor on pointed spaces. Examples : the fundamental of an H-space is abelian.

1.3

Computation of $\pi_1(S^1)$, Applications : Brouwer, d'Alembert...

1.4

The set of free homotopy classes from $S^1$ into a space as the set of conjugacy classes in the fundamental group.

1.5

The fundamental groupoid.

1.6

Definition of higher homotopy groups, examples using the loop space. $\pi_k(S^n)$, $k<n$.

Chapter 2: The Van Kampen Theorem

2.1

The Van Kampen theorem.

2.2

Proof of the Van Kampen theorem.

2.3

Applications : the Nielsen-Schreier theorem. Various computations.

Chapter 3: Covering Spaces

3.1

Definitions and examples.

3.2

Definition of a fibration, a covering space is a fibration.

3.3

The (unique) homotopy lifting property for covering spaces.

3.4

Morphisms of covering spaces.

Chapter 4: Covering Spaces: classification

4.1

Galois covering spaces.

4.2

The equivalence of categories between connected covering spaces over $B$ (conneceted) and $\pi_1(B)$-sets.

4.3

Applications.

4.4

The Van Kampen theorem again.

Chapter 5: Cofibrations

5.1

Definition of cofibrations and of the HEP (homotopy extension property)

5.2

CW-complexes, a CW-pair is a cofibration, applications to quotient spaces.

5.3

Attaching cell to spaces, the behaviour of homotopy groups.  Construction of $K(G,1)$.

5.4

Relative homotopy groups.

5.5

The compression theorem and Whitehead theorem.

If we have enough time we want to do the following

Chapter 6: Additional Topics

6.1

The Blackers-Massey theorem  

6.2

Computation of $\pi_n(S^n)$  

6.3

The nerve of a category and $K(G,1)$.


References

The main textbook will be

C. Godbillon Eléménts de topologie algébrique, Hermann 1998 (in French).

Otherwise we will use

A. Hatcher, Algebraic Topology (available at http://www.math.cornell.edu/~hatcher/AT/AT.pdf)

E. Spanier, Algebraic Topology, Springer 1994

M. Zisman, Topologie algébriqie élémentaire, Armand Colin 1972 (in French)

 

 

Exercises sheet 1