Knot theory

수학노트
http://bomber0.myid.net/ (토론)님의 2010년 8월 11일 (수) 08:36 판
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introduction

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Given a knot and a rational number one can define a closed three-manifold by Dehn surgery

 

 

knot diagram
  • projection to two dimensional space

 

 

Kauffman's principle

 

 

knot invariants
  • Alexander-Conway polynomial
  • Jones polynomial
  • Vassiliev invariants
  • define them recursively using the skein relation
  • Reidemeister's theorem is used to prove that they are knot invariants
  • The puzzle on the mathematical side was that these objects are invariants of a three dimensional situation, but one did not have an intrinsically three dimensional definition.
  • There were many elegant definitions of the knot polynomials, but they all involved looking in some way at a two dimensional projection or slicing of the knot, giving a two dimensional algorithm for computation, and proving that the result is independent of the chosen projection.
  • This is analogous to studying a physical theory that is in fact relativistic but in which one does not know of a manifestly relativistic formulation - like quantum electrodynamics in the 1930's.

 

 

Jones polynomial

 

 

Knot theory, statistical mechanics and quantum groups
  • using the Boltzmann weights from the various exactly solvable models, we can discover an infinite series of invariants of knots
  • so the problem is to find a nice set of Boltzmann weights which give non-trivial invariants

 

 

2+1 dimensional TQFT

 

 

history

 

 

related items

 

books

 

 

encyclopedia[1]

 

 

question and answers(Math Overflow)

 

 

blogs

 

 

articles

 

 

experts on the field

 

 

TeX