Zobrazeno 1 - 10
of 52
pro vyhledávání: '"Ko, Ki Hyoung"'
We first show that the braid group over a graph topologically containing no $\Theta$-shape subgraph has a presentation related only by commutators. Then using discrete Morse theory and triple Massey products, we prove that a graph topologically conta
Externí odkaz:
http://arxiv.org/abs/1407.3723
Autor:
An, Byung Hee, Ko, Ki Hyoung
Publikováno v:
J. Knot Theory Ramification, 22 (2013), no. 6, 1350025, 20pp
We show that there is a family of pseudo-Anosov braids independently parameterized by the braid index and the (canonical) length whose smallest conjugacy invariant sets grow exponentially in the braid index and linearly in the length and conclude tha
Externí odkaz:
http://arxiv.org/abs/1203.2320
Autor:
Ko, Ki Hyoung, Park, Hyo Won
We give formulae for the first homology of the $n$-braid group and the pure 2-braid group over a finite graph in terms of graph theoretic invariants. As immediate consequences, a graph is planar if and only if the first homology of the $n$-braid grou
Externí odkaz:
http://arxiv.org/abs/1101.2648
Publikováno v:
Trans. Amer. Math. Soc. (2010)
We give a necessary and sufficient condition for a graph to have a right-angled Artin group as its braid group for braid index $\ge 5$. In order to have the necessity part, graphs are organized into small classes so that one of homological or cohomol
Externí odkaz:
http://arxiv.org/abs/0805.0082
Autor:
An, Byung Hee, Ko, Ki Hyoung
Publikováno v:
Pacifi J. Math., 247 (2010), no. 2, 257-282
We propose a family of new representations of the braid groups on surfaces that extend linear representations of the braid groups on a disc such as the Burau representation and the Lawrence-Krammer-Bigelow representation.
Comment: 21 pages, 4 fi
Comment: 21 pages, 4 fi
Externí odkaz:
http://arxiv.org/abs/0803.1108
Autor:
Ko, Ki Hyoung, Lee, Jang Won
Random braids that are formed by multiplying randomly chosen permutation braids are studied by analyzing their behavior under Garside's weighted decomposition and cycling. Using this analysis, we propose a polynomial-time algorithm to the conjugacy p
Externí odkaz:
http://arxiv.org/abs/math/0611454
Autor:
Ko, Ki Hyoung, Lee, Jang Won
We propose an algorithm for deciding whether a given braid is pseudo-Anosov, reducible, or periodic. The algorithm is based on Garside's weighted decomposition and is polynomial-time in the word-length of an input braid. Moreover, a reduction system
Externí odkaz:
http://arxiv.org/abs/math/0610746
Autor:
Choi, Doo Ho, Ko, Ki Hyoung
A 1-bridge torus knot in a 3-manifold of genus $\le 1$ is a knot drawn on a Heegaard torus with one bridge. We give two types of normal forms to parameterize the family of 1-bridge torus knots that are similar to the Schubert's normal form and the Co
Externí odkaz:
http://arxiv.org/abs/math/0112102
Autor:
Cha, Jae Choon, Ko, Ki Hyoung
The theory of signature invariants of links in rational homology spheres is applied to covering links of homology boundary links. From patterns and Seifert matrices of homology boundary links, an explicit formula is derived to compute signature invar
Externí odkaz:
http://arxiv.org/abs/math/0108206
Autor:
Cha, Jae Choon, Ko, Ki Hyoung
A theory of signatures for odd-dimensional links in rational homology spheres is studied via their generalized Seifert surfaces. The jump functions of signatures are shown invariant under appropriately generalized concordance and a special care is gi
Externí odkaz:
http://arxiv.org/abs/math/0108197