28 research outputs found
Everywhere Equivalent 3-Braids
A knot (or link) diagram is said to be everywhere equivalent if all the
diagrams obtained by switching one crossing represent the same knot (or link).
We classify such diagrams of a closed 3-braid
Euclidean Mahler measure and twisted links
If the twist numbers of a collection of oriented alternating link diagrams
are bounded, then the Alexander polynomials of the corresponding links have
bounded euclidean Mahler measure (see Definition 1.2). The converse assertion
does not hold. Similarly, if a collection of oriented link diagrams, not
necessarily alternating, have bounded twist numbers, then both the Jones
polynomials and a parametrization of the 2-variable Homflypt polynomials of the
corresponding links have bounded Mahler measure.Comment: This is the version published by Algebraic & Geometric Topology on 7
April 200
Relationships between braid length and the number of braid strands
For a knot K, let b_n(K) be the minimum length of an n-stranded braid
representative of K. Examples of knots exist for which b_n(K) is a
non-increasing function. We investigate the behavior of b_n(K). We develop
bounds on the function in terms of the genus of K, with stronger results for
homogeneous knots and braid positive knots. For knots of nine or fewer
crossings, we show that b_n(K) is an increasing function and determine it
completely.Comment: 9 pages, 2 figures; minor revision
Genus generators and the positivity of the signature
It is a conjecture that the signature of a positive link is bounded below by
an increasing function of its negated Euler characteristic. In relation to this
conjecture, we apply the generator description for canonical genus to show that
the boundedness of the genera of positive knots with given signature can be
algorithmically partially decided. We relate this to the result that the set of
knots of canonical genus greater than or equal to n is dominated by a finite
subset of itself in the sense of Taniyama's partial order.Comment: This is the version published by Algebraic & Geometric Topology on 13
December 200