21 citations · 40 across the 14 of their papers we have counts for
14 papers
Any link has a diagram with only triangles and quadrilaterals
Reiko Shinjo, Kokoro Tanaka
A link diagram can be considered as a -valent graph embedded in the -sphere and divides the sphere into complementary regions. In this paper, we show that any link has a diag…
-knots with the same knot group but different knot quandles
Kokoro Tanaka, Yuta Taniguchi
We give a first example of 2-knots with the same knot group but different knot quandles by analyzing the knot quandles of twist spins. As a byproduct of the analysis, we also give…
Shifting chain maps in quandle homology and cocycle invariants
Yu Hashimoto, Kokoro Tanaka
Quandle homology theory has been developed and cocycles have been used to define invariants of oriented classical or surface links. We introduce a shifting chain map on each qu…
The bridge number of surface links and kei colorings
Kouki Sato, Kokoro Tanaka
Meier and Zupan introduced bridge trisections of surface links in as a 4-dimensional analogue to bridge decompositions of classical links, which gives a numerical invariant o…
Quandle colorings vs. biquandle colorings
Katsumi Ishikawa, Kokoro Tanaka
Biquandles are generalizations of quandles. As well as quandles, biquandles give us many invariants for oriented classical/virtual/surface links. Some invariants derived from biqua…
Independence of Roseman moves including triple points
Kengo Kawamura, Kanako Oshiro, Kokoro Tanaka
Roseman moves are seven types of local modification for surface-link diagrams in -space which generate ambient isotopies of surface-links in -space. In this paper, we focus o…