Piazza Class page.
Week 13: 13 April 2020.
- Opening Remarks:
Do think about your topic for your term paper.
Perhaps it would be a good idea to let me know what you are thinking to write about.
The first chapter concernes the development of Algebraic Number theory.
This is a very beautiful topic concerning generalizations of the integers.
These 'rings of integers' were studied originally as part of attempts to prove Fermat's Last Theorem.
If unique factorization were to hold in them, that approach would have proven Fermat's Last Theorem.
The truth being what it is, we had to move along and adapt to the lack of unique factorization.
That the theory of ideals was able to restore unique facrtorization led to a richer and more abstract connection between algebra and
geometry.
A modern perspective is to create a 'space' whose points are the ideals (actually the prime ideals).
This has its start in the 19th century study of these rings of integers.
For Chapter 22 on Topology.
This culminates in a discussion of one of the great recent results in
mathematics, the proof of the Poincaré conjecture by Perleman, who along the way proved Thurson's geometrization
conjecture.
There were at least four Fields medals related to the settling of the Poincaré conjecture.
As part of Section 22.3, read up on the description of the real projective plane in
Tin Can Topology.
I ask you to read the story of groups in Chapter 23.
It is a bit technical, but was a major focus of algebra for about 30 years, and the story of the finite simple groups is one of the more
accessible parts of modern mathematics (gerbes anyone? or how about geometry over the field with one element? or Drinfeld's chtoucas?).
I hope that you appreciate the story of Conway's discovery of his groups, and the relation of these simple groups to exceptional
structures like the Golay code or the Leech Lattice (a mathematical news story in the past couple of years concerns sphere packing and the
Leech lattice).
Finally, the story of the Monster simple group, as well as the Moonshine conjecture (I understand that Stillwell gets the provenance of
moonshine wrong here) is quite interesting.
It is worth noting that John Thompson and Borcherds both won Fields medals for work in this area.
- Reading:
- Chapters 21, 22, 23 of Stillwell.
- Assignment: Due Monday, 20 April. (HW 14)
To hand in: We are using E-campus for homework submission.
- In Chapter 21, do the exercises 21.2.1, 21.2.2, and 21.7.1.
- In Chapter 22, do the exercises 22.2.2, 22.2.4, 22.2.5 and 22.2.6, the topological proof that there are five Platonic solids.
Last modified: Mon Apr 13 11:53:09 CDT 2020