Jae Choon Cha is Professor of Mathematics and K. W. Kwun Chair Professor at POSTECH.  He is also an Affiliate Professor at KIAS, and an Editor of Bulletin of the Korean Mathematical Society.

1. Universal bounds of Cheeger-Gromov invariants: a topological viewpoint, February 4, 2013, Rice University, Houston, Texas, USA.
2. Covering link calculus and the bipolar filtration of links, The 8th East Asian School of Knots and Related Topics, January 15, 2013, University of Tokyo, Tokyo, Japan.
3. Homology cobordism of 3-manifolds and lower central series, December 4, 2012, Syracuse University, Syracuse, New York, USA.
4. The bipolar filtration of topologically slice links, October 20, 2012, AMS Fall Central Sectional Meeting, Special Session on Knot Theory and 4-manifolds, University of Akron, Akron, Ohio, USA.
5. Amenable L2-signatures and cobordism of knots and 3-manifolds, October 11, 2012, Harvard University, Cambridge, Massachusetts, USA.
6. Homology cobordism and lower central series of 3-manifold groups, October 10, 2012, Brandeis University, Waltham, Massachusetts, USA.
7. Amenable L2-signatures and homology cobordism of 3-manifolds, September 12, 2012, Indiana University, Bloomington, Indiana, USA.
8. Cobordism of knots and 3-manifolds, International Conference of Honam Mathematical Society, June 15, 2012, Jeju National University, Jeju, Korea.
9. Some recent results on links, 3-manifolds, Whitney towers and amenable Cheeger-Gromov invariants, Tokyo workshop on low dimensional topology, March 20, 2012, Tokyo Institute of Technology, Tokyo, Japan.
10. Hidden torsion in 3-manifold groups and homology cobordism, The 8th East Asian School of Knots and Related Topics, January 11, 2012, Daejeon, Korea.
11. An introduction to $L^2$-invariants I, II, III, The 8th East Asian School of Knots and Related Topics, January 9-11, 2012, Daejeon, Korea.
12. Invariants of cobordism of knots and 3-manifolds, Invited talk at 2011 Fall Meeting of Mathematical Society of Japan, September 28, 2011, Shinshu University, Matsumoto City, Nagano, Japan.
Research on Geometric Topology
• Knot theory: placement problems of manifold pairs
• Topology of low dimensional manifolds
• Related algebra, homotopy theory, and L2-invariants

KnotInfo: a table of invariants of classical knots, maintained by Charles Livingston and me.

1. Jae Choon Cha and Mark Powell, Covering link calculus and the bipolar filtration of topologically slice links.
[ Preprint version arxiv:1212.5011 (32 pages) ]
2. Jae Choon Cha, Stefan Friedl, and Mark Powell, Concordance of links with identical Alexander invariants.
[ Preprint version arXiv:1212.2924 (14 pages) ]
3. Jae Choon Cha, Symmetric Whitney tower cobordism for bordered 3-manifolds and links, to appear in Transactions of the American Mathematical Society.
[ Preprint version arXiv:1204.4968 (28 pages) ]
4. Jae Choon Cha and Daniel Ruberman, Concordance to links with unknotted components, Algebraic and Geometric Topology 12 (2012), 963-977.
[ Published version | Preprint version arXiv:1103.2417 ]
5. Jae Choon Cha and Kent E. Orr, Hidden torsion, 3-manifolds, and homology cobordism, to appear in Journal of Topology.
[ Published version | Preprint version arXiv:1101.4092 ]
6. Jae Choon Cha, Taehee Kim, Daniel Ruberman, and Saso Strle, Smooth concordance of links topologically concordant to the Hopf link, Bulletin of the London Mathematical Society 44 (2012), 443-450.
[ Published version | Preprint version arXiv:1012.2045 ]
7. Jae Choon Cha, Amenable $L^2$-theoretic methods and knot concordance, to appear in International Mathematics Research Notices (IMRN).
[ Preprint version arXiv:1010.1058 (25 pages) ]
8. Jae Choon Cha and Stefan Friedl, Twisted torsion invariants and link concordance, to appear in Forum Mathematicum.
[ Published version | Preprint version arXiv:1001.0926 ]
9. Jae Choon Cha and Kent E. Orr, $L^2$-signatures, homology localization, and amenable groups, Communications on Pure and Applied Mathematics 65 (2012), 790-832.
[ Published version | Preprint version arXiv:0910.3700 ]
10. Jae Choon Cha, Stefan Friedl, and Taehee Kim, The cobordism group of homology cylinders, Compositio Mathematica 147 (2011), 914-942.
[ Published version | Preprint version arXiv:0909.5580 ]
11. Jae Choon Cha, Link concordance, homology cobordism, and Hirzebruch-type defects from iterated p-covers, Journal of the European Mathematical Society (JEMS) 12 (2010), 555-610.
[ Published version | Preprint version arXiv:0705.0088 ]
12. Jae Choon Cha, Structure of the string link concordance group and Hirzebruch-type invariants, Indiana University Mathematics Journal 58 (2009), 891-928.
[ Published version | Preprint version arXiv:0709.2968 ]