## Jang YeonheeFaculty Division of Natural Sciences Research Group of Mathematics Associate Professor |

Last Updated :2021/10/20

- 3次元多様体論 結び目理論 3-dimensional manifolds Knot Theory

- Jan. 2019, Nara Women's University, Faculty, Division of Natural Sciences, 准教授
- Apr. 2013 Dec. - 2018, Nara Women's University, Faculty, Division of Natural Sciences, 助教
- 2012 - 2013, 日本学術振興会外国人特別研究員
- 2012 - 2013, :JSPS Foreign Research Fellow
- 2013, -:Nara Women's University, Assistant Professor
- 2010 - 2012, 日本学術振興会特別研究員
- 2010 - 2012, :JSPS Research Fellow

- Apr. 2008, Mar. - 2011, Hiroshima University, 理学研究科, 数学専攻, Japan
- - 2011, Hiroshima University, Graduate School of Sciences, Department of Mathematics
- Apr. 2006, Mar. - 2008, Osaka University, 理学研究科, 数学専攻, Japan
- - 2008, Osaka University, Graduate School of Sciences, Department of Mathematics
- Mar. 2000, Aug. - 2004, 全北大学校, 師範大学, 数学教育学科, Korea, Republic of
- - 2004, Chonbuk National University, College of Education, Department of Mathematics Education, Korea, Republic of

On keen Heegaard splittings

Oct. 2018, Adv. Stud. Pure Math., 78, 293 - 311Meridional rank and bridge number for a class of links

We prove that links with meridional rank 3 whose 2-fold branched covers are graph manifolds are 3-bridge links. This gives a partial answer to a question by S. Cappell and J. Shaneson on the relation between the bridge numbers and meridional ranks of links. To prove this result, we also show that the meridional rank of any satellite knot is at least 4., University of California, Berkeley, 2018, Pacific Journal of Mathematics, 292 (1), 61 - 80, doiScientific journal

Meridional rank of knots whose exterior is a graph manifold

We prove for a large class of knots that the meridional rank coincides with the bridge number. This class contains all knots whose exterior is a graph manifold. This gives a partial answer to a question of S. Cappell and J. Shaneson [10, pb 1.11]. (C) 2017 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Sep. 2017, TOPOLOGY AND ITS APPLICATIONS, 228, 458 - 485, doi;web_of_scienceScientific journal

A knot with destabilized bridge spheres of arbitrarily high bridge number

We show that there exists an infinite family of knots, each of which has, for each integer k >= 0, a destabilized (2k + 5)-bridge sphere. We also show that, for each integer n >= 4, there exists a knot with a destabilized 3-bridge sphere and a destabilized n-bridge sphere., OXFORD UNIV PRESS, Apr. 2016, JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES, 93 (2), 379 - 396, doi;web_of_scienceScientific journal

Bridge splittings of links with distance exactly n

We show that, for any integers n >= 2, g >= 0 and b >= 1 except for (g, b) = (0,1) and (0, 2), there exists a (g, b)-bridge splitting of a link in some manifold with distance exactly n. (C) 2015 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Dec. 2015, TOPOLOGY AND ITS APPLICATIONS, 196, 608 - 617, doi;web_of_scienceScientific journal

Distance of bridge surfaces for links with essential meridional spheres

Bachman and Schleimer gave an upper bound for the distance of a bridge surface of a knot in a 3-manifold which admits an essential surface in the exterior. Here we give a sharper upper bound for the distance of a bridge surface of a link when the manifold admits an essential meridional sphere in the exterior., PACIFIC JOURNAL MATHEMATICS, Jan. 2014, PACIFIC JOURNAL OF MATHEMATICS, 267 (1), 121 - 130, doi;web_of_scienceScientific journal

Heegaard splittings of distance exactly n

In this paper, we show that, for any integers n >= 2 and g >= 2, there exist genus-g Heegaard splittings of compact 3-manifolds with distance exactly n., GEOMETRY & TOPOLOGY PUBLICATIONS, 2014, ALGEBRAIC AND GEOMETRIC TOPOLOGY, 14 (3), 1395 - 1411, doi;web_of_scienceScientific journal

Classification of 3-bridge spheres of 3-bridge arborescent links

In this paper, we give an isotopy classification of 3-bridge spheres of 3-bridge arborescent links, which are not Montesinos links. To this end, we prove a certain refinement of a theorem of J. S. Birman and H. M. Hilden [3] on the relation between bridge presentations of links and Heegaard splittings of 3-manifolds. In the proof of this result, we also give an answer to a question by K. Morimoto [23] on the classification of genus-2 Heegaard splittings of certain graph manifolds. © 2013 The Mathematical Society of Japan., 2013, Journal of the Mathematical Society of Japan, 65 (1), 97 - 136, doiScientific journal

A G-family of quandles and handlebody-knots

2013, Illinois Journal of Mathematics, 57 (3), 817 - 838Symmetric quandle colorings for spatial graphs and handlebody-links

In this paper, colorings by symmetric quandles for spatial graphs and handlebody-links are introduced. We also introduce colorings by LH-quandles for LH-links. LH-links are handlebody-links, some of whose circle components are specified, which are related to Heegaard splittings of link exteriors. We also discuss quandle (co)homology groups and cocycle invariants., WORLD SCIENTIFIC PUBL CO PTE LTD, Apr. 2012, JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS, 21 (4), doi;web_of_scienceScientific journal

Characterization of 3-bridge links with infinitely many 3-bridge spheres

In an earlier paper, the author constructed an infinite family of 3-bridge links each of which admits infinitely many 3-bridge spheres up to isotopy. In this paper, we prove that if a prime, unsplittable link L in S-3 admits infinitely many 3-bridge spheres up to isotopy then L belongs to the family. (C) 2011 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Mar. 2012, TOPOLOGY AND ITS APPLICATIONS, 159 (4), 1132 - 1145, doi;web_of_scienceScientific journal

Classification of 3-bridge arborescent links

In this paper, we give a complete classification of 3-bridge arborescent links., HIROSHIMA UNIV, GRAD SCH SCI, Mar. 2011, HIROSHIMA MATHEMATICAL JOURNAL, 41 (1), 89 - 136, web_of_scienceScientific journal

Three-bridge links with infinitely many three-bridge spheres

we construct infinitely many three-bridge links each of which admits infinitely many three-bridge spheres up to isotopy. (C) 2009 Elsevier B.V. All rights reserved., ELSEVIER SCIENCE BV, Jan. 2010, TOPOLOGY AND ITS APPLICATIONS, 157 (1), 165 - 172, doi;web_of_scienceScientific journal

On 2-twist-spun spherical Montesinos knots

Dec. 2020, Journal of Knot Theory and Its Ramifications, 29 (14)Scientific journal

Double branched covers of tunnel number one knots

Apr. 2021, Geometriae Dedicata, 211 (1), 129 - 143Scientific journal

Extending geodesics in the curve complex

2013, RIMS kokyuroku, 1836, 1 - 6(1,1)-bridge splitting with distance exactly n

2013, RIMS kokyuroku, 1868, 32 - 37

Bridge splittings of links as viewed from the curve complex

Women in Mathematics - a Panorama of Contributions, 2017Knots with non-minimal dstabilized bridge spheres

The 6th TAPU-KOOK Joint Seminar on Knots and Related Topics, 2014Bridge splittings of links with Hempel distance n

A Satellite Conference of Seoul ICM 2014: Knots and Low Dimensional Manifolds, 2014