2 papers
math.GT2026
On the crossing number of knots and links on surface in 3-manifolds
Tetsuya Ito
We give a lower bound of the minimum crossing number of knots and links projected on a 2-sided surface in a 3-manifold using the rank of fundamental groups which means that the cro…
math.GT2025
Ma-Qiu index, presentation distance, and local moves in knot theory
Tetsuya Ito
The Ma-Qiu index of a group is the minimum number of normal generators of the commutator subgroup. We show that the Ma-Qiu index gives a lower bound of the presentation distance of…