CUHK MATH Polynomial

Tie me up, Tie me down
 
Equivalence
Trefoil
Figure Eight
Whitehead
Trivial Knot
Perko Pairs
 
Classifications
Torus Knots
Alternating Knots
 
Invariants
Crossing number
Bridge number
Unknotting number
Tricolorability
Linking number
Polynomials
Left trefoil Right trefoil

Left trefoil and Right trefoil are mirror images to each other.

Polynomial is the only invariant that we can prove they are different.

Name Figure Jones Polynomial
Left trefoil -1/t4 + 1/t3 + 1/t
Right trefoil t + t3 - t4


One More Mirror Image:

Polynomial: 1/t2 - 1/t + 1 + t + t2

This one is "symmetric".


More Examples:
Figure Jones Polynomial
-1/t3 - 1/t2 + 2/t -3 + 3t - 3 t2 +3 t4 - 2 t2 + t5
-1/t +2 -t +2 t2 -t4 + t2 -t5
1/t7 - 2/t6+2/t5 - 3/t4 +3/t3 - 2/t2 + 2/t
-1/t8 + 1/t5 +1/ t3

History of Polynomials

  • 1929 J. Alexander
  • 1958 Conway-Alexander
  • 1984 Vaughan Jones
  • then many others
For all these polynomials, there may be different knots having the same polynomial.