Málstofa í stærðfræði

Fyrirlesari: Marston Conder, University of Auckland

Titill: Experimental Algebra and Combinatorics

Staðsetning: Tg-227 (Tæknigarður, 2. hæð)
Tími: Fimmtudagur 13. júlí kl. 11:00

Ágrip:

Some 40 years after the computer-based proof of the 4-Colour Theorem by Appel and Haken, there is still a degree of healthy skepticism about the use of computers to prove nice theorems in mathematics. But there is a distinction between proofs that are highly dependent on computation (verifiable or otherwise), and the use of computer-based experimentation to analyse and construct examples, to produce data that might exhibit patterns from which conjectures can be drawn and tested, or to investigate a range of possible scenarios — subsequently leading to theorems that can be proved by hand.
In this talk I will describe a range of instances of experimental computations involving finite and infinite groups that have led to unexpected but theoretically provable discoveries about discrete objects possessing a high degree of symmetry. These include discoveries about the genus spectra of particular classes of regular maps on surfaces, the smallest regular and chiral polytopes, and various kinds of edge-transitive graphs. Such examples highlight the value of experimental computation, and the surprising outcomes it can often produce.