SYMMETRY BREAKING IN TORUS KNOTS

SMALL TORUS KNOTS

     Let us consider one of the simplest type of prime knots: torus T2,n knots, whose n-fold symmetrical conformations are easily defined parametrically. For n=3, i.e. the 31 (trefoil) knot, its final, tight conformation preserves the 3-fold symmetry of the initial conformation. For n=5, i.e. the 51 knot, the 5-fold symmetry of the initial conformation becomes broken during the tightening process. See figure below.


LARGE TORUS KNOTS

For much larger n, the evolution of the symmetrical, parametrically defined torus knots towards their most tight conformations is a complex process. Figures below show its consecutive stages in the cases of n=33 and n=99.


n=33
 


n=99

 Further simulations performed with larger T2,n torus knots prove that the shapeless, blob-like conformation shown at the last frame above is not the best one. Starting from a different initial conformation of the knot we find a different final conformation, which proves to be slightly better from the point of view of the length of the rope used to tie it. See below.
 
 


Initial linear conformation


 Twisted final conformation

OPEN QUESTION: Are there any better conformations?

The problem of ideal T2,n torus knots is closely related to the problem of the ideal twisted pair.

Back to the index page