activity
20152026
most citedA lower bound on minimal number of colors for links

5 citations · 5 across the 10 of their papers we have counts for

collaborators

11 papers

math.GT2026

The minimum number of Dehn -colors of any nonsplittable -colorable link is three

Eri Matsudo, Kanako Oshiro

Our previous papers [8, 9] are the first and second to discuss minimum numbers of ``region'' colors, while minimum numbers of arc colors such as Fox colors are well-studied. As the…

math.GT2025

Minimum numbers of Dehn colors of knots and symmetric local biquandle cocycle invariants

Eri Matsudo, Kanako Oshiro, Gaishi Yamagishi

In this paper, we give a method to evaluate minimum numbers of Dehn colors for knots by using symmetric local biquandle cocycle invariants. We give answers to some questions arisin…

math.GT2025

Minimum numbers of Dehn colors of knots and -palette graphs

Eri Matsudo, Kanako Oshiro, Gaishi Yamagishi

In this paper, we consider minimum numbers of colors of knots for Dehn colorings. In particular, we will show that for any odd prime number and any Dehn -colorable knot ,…

math.GT2023

Two-tone colorings and surjective dihedral representations for links

Kazuhiro Ichihara, Katsumi Ishikawa, Eri Matsudo +1

It is well-known that a knot is Fox -colorable for a prime if and only if the knot group admits a surjective homomorphism to the dihedral group of degree . However, this…

math.GT2022

Constructing Goeritz matrix from Dehn coloring matrix

Masaki Horiuchi, Kazuhiro Ichihara, Eri Matsudo +1

Associated to a knot diagram, Goeritz introduced an integral matrix, which is now called a Goeritz matrix. It was shown by Traldi that the solution space of the equations with Goer…

math.GT2021

Coloring links by the symmetric group of degree three

Kazuhiro Ichihara, Eri Matsudo

We consider the number of colors for the colorings of links by the symmetric group of degree . For knots, such a coloring corresponds to a Fox 3-coloring, and thus the num…

math.GT2019

Minimal coloring numbers on minimal diagrams of torus links

Kazuhiro Ichihara, Katsumi Ishikawa, Eri Matsudo

We determine the minimal number of colors for non-trivial -colorings on the standard minimal diagrams of -colorable torus links. Also included are complete…

math.GT2017

Minimal coloring number on minimal diagrams for -colorable links

Kazuhiro Ichihara, Eri Matsudo

It was shown that any -colorable link has a diagram which admits a non-trivial -coloring with at most four colors. In this paper, we consider minimal number…

math.GT2017

Minimal coloring number for -colorable links II

Eri Matsudo

The minimal coloring number of a -colorable link is the minimal number of colors for non-trivial -colorings on diagrams of the link. In this paper, we show…

math.GT2016

Minimal coloring number for Z-colorable links

Kazuhiro Ichihara, Eri Matsudo

For a link with zero determinants, a Z-coloring is defined as a generalization of Fox coloring. We call a link having a diagram which admits a non-trivial Z-coloring a Z-colorable…

math.GT2015★ 5 cited

A lower bound on minimal number of colors for links

Kazuhiro Ichihara, Eri Matsudo

We show that the minimal number of colors for all effective -colorings of a link with non-zero determinant is at least .