University of Durham --- Department of Mathematical Sciences



MATH2141 MATH2151 Geometric Topology.


Epiphany 2015





Lecturer: Andrew Lobb

Schedule:





Books

Dirk Schuetz has kindly provided a copy of his typed lecture notes for this course. We shall be following Dirk's lecture notes by-and-large, although we may well emphasize things a little differently or give alternative derivations and examples. These notes should be your first port of call. After this, there are a number of good books out there covering much of our material; you should look out for the books written by





Lectures

Here's a brief outline of what I intend to cover in each week's lectures.


Week

Content

1

Knots and links intuitively. The Reidemeister moves. Tri-colorings.

2

Crossing number, composition of knots, alternating knots.

3

Writhe, linking number, the bracket and X polynomials.

4

Alexander polynomial, absolute polynomial, beginnings of the topology of surfaces.

5

Simplicial complexes, triangulations, Euler characteristic.

6

Surfaces with boundary, classification theorem, Seifert surfaces.

7

Seifert surfaces continued, genus of a knot, winding number.

8

Vector fields in the plane, singularities, index, tangent curves.

9

Vector fields on surfaces, hairy ball theorem, Poincare-Hopf theorem.





Assignments

Your homework is handed in at 5:30pm on Thursdays. Solutions will be posted shortly afterwards. Not every question is to be handed in for marking - this is indicated in the table below. We'll do some of the other questions in the tutorials and problems classes.


Exercise Sheet

Date due

Questions to hand in

Solutions

Sheet 1.

22nd January

1,5,8.

Solutions 1.

Sheet 2.

29th January

3,4.

Solutions 2.

Sheet 3.

5th February

3,10.

Solutions 3.

Sheet 4.

12th February

1(a), 3 (for "Jones" please read "X").

Solutions 4.

Sheet 5.

19th February

2 (for "Jones" read "X"), 6 (for "Jones" read "X").

Solutions 5.

Sheet 6.

26th February

2(a), 3.

Solutions 6.

Sheet 7.

5th March

1, 4.

Solutions 7.

Sheet 8.

12th March

2, 4.

Solutions 8.

Sheet 9.

No date.

For exam practice.

Solutions 9.