# Talks

IBS-DIMAG seminar, TBD.

The Pacific Rim Mathematical Association Congress 2021 (PRIMA CONGRESS 2021), Special Session on ``Geometric Group Theory'', December 2022 (TBD).

The Mathematical Society of Japan -- Seasonal Institute (MSJ-SI), New aspects of Teichmüller theory, University of Tokyo, Japan, July 17 - 30, 2022.

Geometry and Analysis on Groups Research Seminar, University of Vienna, June 7, 2022.

OpenKIAS Public Lecture, Korean Mathematical Society, April 28, 2022 (5pm), hybrid.

Sydney Mathematical Research Institute (SMRI) Algebra and Geometry Online seminar, March 2nd, 2022 (Wed, 11 am KST/ 1 pm Australia). [youtube]

Future intelligence (forum), CHUNG MONG-KOO Foundation and Chosun Ilbo, February 17, 2022. [youtube] [youtube (sketch)]

Samsung Sciences & Technology Foundation Annual Forum, November 22, 2021.

Geometry and Topology Online, Warwick Mathematics Institute, November 18, 2021 (online).

Symmetry in Newcastle (seminar), The University of Newcastle, Australia, November 1, 2021 (online). [youtube]

Graduate seminar on mathematical challenges, Yonsei University, October 6, 2021.

VI Congreso Latinoamericano de Matemáticos (CLAM) 2021, Montevideo, Uruguay, September 14, 2021 (online).

REU Colloquium, University of Virginia, July 21, 2021 (online).

Mathematical Sciences Department colloquium, Seoul National University, May 6, 2021. "On Circle Diffeomorphism Groups" (online).

The 16th East Asian Conference on Geometric Topology, University of Tokyo, Japan, January 25, 2021. (online)

Expanding Dynamics, CMM - Center for Mathematical Modeling / Universidad de Chile, October 13, 2020. (online)

Teichmüller Theory: Classical, Higher, Super and Quantum, CIRM, Luminy, France, October 8, 2020. (online)

The 3rd International Undergraduate Mathematics Summer School, Seoul National University,TBD, 5 lectures, postponed.

Mathematics Colloquium, Seoul National University, Korea, TBD. Groups of circle diffeomorphisms: analysis, dynamics and algebra, postponed.

REU Colloquium, University of Virginia, June 24, 2020 (online).

Colloquium at Electrical Engineering School, DGIST, Korea, June 2, 2020 (online).

Hyperbolic Lunch, University of Toronto, May 13, 2020. (online)

Virtual Seminar on Geometry and Topology (visgat), KIAS and KAIST, March 31, 2020. (online)

Topology Seminar, Gakushuin University, December 2, 2019.

Mathematics Colloquium, KAIST, November 21, 2019.

Mathematics Colloquium, Korea University, November 15, 2019.

Arbeitsgemeinschaft: Zimmer's Conjecture, Mathematisches Forschungsinstitut Oberwolfach, Germany, 13 -- 18 October, 2019. Title: Property T and actions on S^1.

Geometry and Analysis on Groups Seminar, University of Vienna, Austria, October 8, 2019.

Summer School on Geometric Topology and Algebraic Geometry, KAIST, Korea, August 12 an 13, 2019.

Combinatorial and algebraic aspects of geometric structures – Workshop in Thailand, with the cooperation of Luxembourg, Singapore, and Thailand, Chiang Mai, Thailand, July 18 and 19, 2019.

Ordered Groups and Rigidity in Dynamics and Topology, Oaxaca, Mexico, June 17, 2019.

Undergraduate seminar, Kwangwoon University, June 7, 2019.

International Conference Complex Analysis, Partial Differential Equations And Their Applications, Hanoi, Vietnam, June 5, 2019. *My talk was on June 5, but it did not appear in the webpage for some reason.

Ergodic and Geometric Group (EGG) Theory seminar, EPFL, Lausanne, Swiss, May 27, 2019.

Non-positive curvature, Warsaw, Poland, May 20, 2019.

Geometry and Analysis on Groups Seminar, University of Vienna, Austria, May 16, 2019.

Special Sessions on Mapping Class Groups, University of Hawaii at Manoa, Honolulu, US, March 23, 2019.

East Asian Conference of Geometric Topology, Beijing, China, January 23, 2019.

Suzhou 2019 Workshop on Geometry Topology, Soochow University, Suzhou, China, January 18, 2019.

Boundaries of topological groups, C*-algebras, symmetric spaces, and Lyapounov exponents, TSIMF, Sanya, China, December 20, 2018.

One-day Workshop about Dynamics, Geometry and Groups, Suwon, Korea, December 5, 2018.

KIAS Analysis Seminar, Seoul, Korea, November 1, 2018.

New Trends in Teichmüller Theory and Mapping Class Groups, Mathematisches Forschungsinstitut Oberwolfach, Germany, September 2--8, 2018.

Department Seminar, Chiang Mai University, Thailand, August 24, 2018.

International Conference on Dynamical Systems, Sustech, China, June 25--28, 2018. Slide (PDF)

Hyperbolic 3-manifolds and related topics, Postech, Korea, June 18-- 22, 2018.

Silk Road Geometry Conference, Gokova Geometry/Topology Institute (GGTI), Turkey, June 4 - 8, 2018.

Topology in Australia and South Korea, IBS-CGP, Korea, April 25--27, 2018.

KIAS (Korea Institute for Advanced Study), Korea, April 17, 2018.

Topology Seminar, KAIST, Korea, March 27, 2018.

Branched Coverings, Degenerations, and Related Topics 2018 (minicourse), Hiroshima University, Japan, March 5 - 9, 2018.

Structure of 3-manifold Groups, CIRM (Luminy), France, February 26 - March 2, 2018.

Workshop on Geometric Group Theory (minicourse), BICMR, Beijing University, December 16 - 17, 2017.

Kyoto University, December 12, 2017.

Low-dimensional topology seminar, Osaka University, December 5, 2017.

Topology Seminar, University of Tokyo, November 28, 2017.

Max Dehn Seminar, University of Utah, October 25, 2017.

Topology Seminar, Rice University, October 23, 2017.

Topology Seminar, University of Texas at Austin, October 20, 2017.

Colloquium, University of Virginia, October 12, 2017.

Geometric Group Theory and Topology Seminar, Tufts University, October 3, 2017.

Geometry and Topology Seminar, Brown University, September 29, 2017.

GGT Seminar, MgGill University, September 27, 2017.

Japan Conference on Discrete and Computational Geometry, Graphs, and Games: JCDCG3, Tokyo University of Science (Aug 29 - Sep 1), Tokyo, Japan, August 29, 2017.

Japanese Topology Symposium, Tokai University, Tokyo, Japan, August 21 -- 24, 2017, 2017.

Invited talk, Korea Institute for Advanced Study (KIAS), Korea, Aug 7, 2017.

GAGTA 2017: Geometric and Asymptotic Group Theory with Applications (July 3 -- 7), Bilbao, Spain, July 4, 2017.

SFB Seminar, Universität Regensburg, Germany, June 30, 2017.

Séminaire Géométrie, Dynamique et Topologie (GDT), L’Institut de Mathématiques de Marseille (I2M), France, May 22, 2017.

Geometry Seminar, ETH Zürich, Swiss, May 3, 2017.

Ergodic and Geometric Group (EGG) Theory seminar, EPFL, Lausanne, Swiss, April 27, 2017.

Thursday Colloquium, TIFR, Mumbai, India, April 20, 2017.

IBS--CGP Seminar, Pohang, Korea, April 13, 2017.

Department Colloquium, Sungkyunkwan University, Suwon, Korea, April 6, 2017.

Topology--Geometry Seminar, Hiroshima University, Japan, March 16, 2017.

Topology Seminar, Osaka University, Japan, March 13, 2017.

SNU Geometry and Topology Mini-Workshop, Seoul National University, Korea, February 17, 2017.

SNU Topology Winter School, December 16,, 2016.

Virginia Topology Conference, University of Virginia, November 18, 2016.

Geometry and Topology Seminar, Seoul National University, November 16, 2016.

Topology Seminar, Sungkyunkwan University, November 15, 2016.

Invited Talk, Korean Mathematical Society Annual Fall Conference, October 22, 2016.

Workshop on Moduli Spaces of Geometric Structures, a part of the summer-long program Geometry, Topology and Dynamics of Moduli Spaces, National University of Singapore, August 17, 2016.

Geometric Topology Fair 2016, KAIST, Daejeon, July 7, 2016.

GAGTA (Geometric and Asymptotic Group Theory and Applications) 2016, Stevens Institute of Technology, June 17, 2016.

IBS--CGP seminar, IBS--CGP, Pohang, Korea, April 21, 2016.

Mathematics seminar, Konkuk University, Seoul, Korea, March 25, 2016.

Invited lecture, Korea Institute for Advanced Study (KIAS), Korea, Mar 2, 2016.

Group actions seminar, Yale University, Feb 22, 2016.

Geometry and topology seminar, Univ. of Massachusetts at Amherst, Feb 19, 2016.

Geometric group theory seminar, Tufts University, Feb 18, 2016.

Teichmüller theory and low-dimensional topology, Tsinghua Sanya International Mathematics Forum (TSIMF), China, Jan 11 - 15, 2016. script

East Asian Conference on Algebraic Topology 6 (EACAT-6), Daejeon, November 30 - Dec 4, 2015.

2015 International Workshop on Mathematical Sciences in Dalian, China, Oct 30 - Nov 1, 2015.

Department Colloquium, Ewha Women's University, Oct 15, 2015.

University of Rennes, France, October 1, 2015.

IBS--CGP Mathematics Festival for Undergraduates, Aug 17 - 21, 2015. script

Dubrovnik VIII - Geometric Topology, Geometric Group Theory and Dynamical Systems, Croatia, June 22 - 26, 2015.

Statistics seminar, Seoul National University, Korea, June 4, 2015.

Geometry & Topology seminar, Postech, Korea, April 22, 2015.

Geometric Group Theory on Gulf Coast (G^3), San Padres Island, USA, March 26 - 29, 2015.

KIAS Algebra Seminar, KIAS, January 5, 2015.

Group Action Forum, Tsinghua Sanya International Mathematics Forum, China, December 15 -- 19, 2014.

KIAS/CMC Colloquium, KIAS, December 2, 2014.

Department Colloquium, Chiang Mai University, October 28, 2014.

the 7th Mathematical Society of Japan -- Seasonal Institute (MSJ-SI), Hyperbolic Geometry and Geometric Group Theory (ICM Satellite), University of Tokyo, Japan, July 30 - August 5, 2014. script

Discrete Groups and Geometric Structures with Applications V, KU Leuven, Belgium, June 2 - 6, 2014.

Seoul National University Department Colloquium,

*Subgroups of Mapping Class Groups*, March 13, 2014Branched Coverings, Degenerations, and Related Topics 2014, Hiroshima University, Japan, March 7, 2014.

Groups and Geometry in the South East, Mathematics Institute, Warwick University, United Kingdom, February 21, 2014.

Complex Analysis and Topology of Discrete Groups and Hyperbolic Spaces, Research Institute for Mathematical Sciences, Kyoto University, Japan, January 24, 2014.

5th East Asian Conference of Algebraic Topology (EACAT 5), Chinese Academy of Sciences, Beijing, China, December 3, 2013.

Wasatch Topology Conference, the University of Utah, USA, November 16, 2013.

Topology Seminar, University of Texas at Austin, November 11, 2013.

Geometry and Topology Seminar, City University of New York, November 5, 2013.

Discovery-oriented class in calculus, Inha University Pedagogy Workshop, October 28, 2013. script

Korean Mathematical Society Annual Meeting, University of Seoul, Korea, October 25, 2013.

Geometry and Topology Seminar, Brown University, October 9, 2013.

Topology/Geometry Seminar, Yale University, October 8, 2013.

New York Applied Algebra Colloquium, City University of New York, 27 September, 2013.

Geometric and Analytic Group Theory, Ventotene Island, Italy, September 9-14, 2013.

Geometric Structures on Low-Dimensional Manifolds, Korea Institute for Advanced Study, Korea, May 24, 2013.

Discrete Math Seminar, KAIST, April 19, 2013.

Hot Topics: Surface subgroups and cube complexes, Mathematical Sciences Research Institute, USA, March 19, 2013.

Topology and Geometry Seminar, National University of Singapore, February 13, 2013.

Geometric Group Theory and Topology Seminar, Tufts University, January 29, 2013.

Topology/Geometry Seminar, Yale University, January 22, 2013.

Manhattan Algebra Day, Stevens Institute, USA, December 7, 2012.

Topology Seminar, Osaka University, December 4 2012.

Friday Workshop on Geometry of Artin Groups, KIAS, November 23, 2012.

Topology Seminar, Hanyang University, October 19 and October 26, 2012.

Department Colloquium, Sogang University, October 18 2012.

MSJ-KMS Joint Meeting, Kyushu University, Japan, September 17, 2012. script

Topology Seminar, KAIST, September 5 2012.

The 10th KAIST Geometric Topology Fair, KAIST, Daejeon, Korea, August 16, 2012.

Geometric and Asymptotic Group Theory with Applications (GAGTA-6), University of Duesseldorf, July 30, 2012.

Geometric Group Theory - Kyoto 2012, Kyoto University, Japan, June 7, 2012.

Department Colloquium, Ulsan University, April 12 2012.

Workshop on Immersed surfaces in 3-manifolds, a part of the IHP program "Geometry and analysis of surface group representations", IHP, Paris, March 26, 2012. script

Geometry and Topology Seminar, SUNY Buffalo, January 25, 2012.

AMS-MAA Joint Meeting, Special session on hyperbolicity in manifolds and groups, Boston, January 4, 2012.

Department Colloquium, Konkuk University, Seoul, Korea, November 17, 2011.

Department Colloquium, Hanyang University, Seoul, Korea, November 4, 2011.

Department Colloquium, Yonsei University, Seoul, Korea, October 13, 2011.

Department Colloquium, Seoul National University, Seoul, Korea, September 29, 2011.

The 4th Topology Workshop, Chonbuk National University, Jeonju, Korea, August 23 - 24, 2011.

The 9th KAIST Geometric Topology Fair, KAIST, Daejeon, Korea, August 9, 2011.

Geometric and Asymptotic Group Theory with Applications (GAGTA--5), Universitat Politecnica de Catalunya, Barcelona, Spain, July 12, 2011.

Dubrovnik VII - Geometric Topology, Inter-University Centre and University of Zagreb, Dubrovnik, Croatia, July 2, 2011.

Geometry/Topology Seminar, University of Chicago, April 12, 2011.

Topology/Geometry Seminar, Yale University, April 5, 2011.

Spring Topology and Dynamics Conference, University of Texas at Tyler, U.S.A., March 18, 2011.

AMS Southeastern Section Meeting, Special Session on Geometric Group Theory, Georgia Southern University, U.S.A., March 13, 2011.

Topology and Geometric Group Theory Seminar, Cornell University, March 8, 2011.

Bernstein Seminar, Cornell University, March 8, 2011.

AMS-MAA Joint Meeting, Special session on groups, geometry and applications, New Orleans, January 7, 2011.

Topology Seminar, KAIST, Korea, December 23, 2010.

Geometry and Topology Seminar, SUNY Buffalo, November 19, 2010.

Topology Seminar, University of Texas at Austin, November 8, 2010.

Geometry and Topology Seminar, Caltech, October 22, 2010.

Approaches to Group Theory, Using Algebraic, Analytic, and Geometric Tools in the Study of Groups, Cornell University, U.S.A., October 10, 2010.

Topology Seminar, Brandeis University, September 21 2010.

Geometric Group Theory and Topology Seminar, Tufts University, September 14, 2010.

KAIST Topology Workshop, Daejeon, Korea, August 4, 2010.

KAIST--POSTECH--SNU YB Workshop, Jeonju, Korea, July 3, 2010.

Topology Seminar, University of California at Santa Barbara, May 18, 2010.

AMS Special Session on Geometric Group Theory, University of New Mexico, U.S.A., April 18 2010.

Geometric Group Theory Seminar, Tufts University, January 19, 2010.

BK21 Seminar, KAIST, January 26 2010.

Joint Topology and Discrete Math Seminar, KAIST, December 28, 2009.

Topology Seminar, Konkuk University, December 22, 2009.

Joint Meeting of Korean Mathematical Society and American Mathematical Society, Special Session on Geometric Structures and Geometric Group Theory, Ewha Womans University, Korea, December 18, 2009.

Topology/Geometry Seminar, Yale University, October 27, 2009.

Topology Seminar, The University of Texas at Austin, August 31, 2009.

International Conference on Geometric and Combinatorial Methods in Group Theory and Semigroup Theory, the University of Nebraska-Lincoln, U.S.A., May 20, 2009.

AMS Special Session on Recent Progress in Geometric Group Theory, San Francisco State University, April 25, 2009.

Topology Seminar, The University of Texas at Austin, April 13, 2009.

Groups and Dynamics Seminar, Texas A&M University, March 25, 2009.

Topology Seminar, The University of Texas at Austin, October 27, 2008. script

Groups and Infinite Graphs, Erwin Schroedinger International Institute, Austria, August 26, 2008.

Topology Seminar, Seoul National University, Korea, June 2, 2008.

Topology Seminar, The University of Texas at Austin, January 28, 2008. script

Joint Postdoc Seminar, Mathematics Sciences Research Institute, October 19 2007.

Group Actions Seminar, Yale University, October 16, 2006.

Student Seminar (exposition), Yale University, May 1, 2004. script

## Public lectures

"인간, 수학, 컴퓨터", KFAS Webinar, Youtube Live, November 13, 2021.

OpenKIAS public lecture - 불가능에 대하여 (갈루아, 괴델, 튜링, 힐버트), December 22, 2020. online

이토록 황홀한 수학 (Fascinated by Mathematics), a series of 11 lectures on various subjects, EBS2 channel (Korean Educational Broadcasting System), August 19 - September 2, 2020. lecture 1 (youtube) complete lectures

Public lecture (organized by The Korean Academy of Science and Technology), Yeongnam High School, Daegu, Korea, April 3, 2019.

Public lecture at Mathematics Culture Festival, Gwachun National Science Museum, Korea, April 27, 2019.

Science Camp, College of Natural Sciences, Seoul National University, (1) August 3, 2016 (2) August 9, 2018

Talk concert (for general public), Gwachun National Science Museum, Korea, Aug 19, 2017.

Young Mathematicians' Camp, National Institute for Mathematical Sciences, Daejeon, February 22, 2017.

College of Natural Sciences Public Lecture, Seoul National University, Korea, February 9, 2017. [youtube]

Saturday Public Science Lectures, College of Natural Sciences, Seoul National University, March 26, 2016.

Saturday Public Science Lecture, College of Natural Sciences, Seoul National University, Oct 24, 2015.

Dream Lecture Series by Korea Foundation for Advanced Studies

Human, Mathematics, Computer (On the Halting problem of Turing), KFAS building, November 13, 2021 (online).

*2018*May 12 (KFAS building), May 14 (Hanyoung Foreign Language High School)*2017*March 20, 2017 (Young-rak High School), July 15, 2017 (KFAS building).*2016*July 23, July 30 (KFAS building), Seoul High School, October 14.*2015*Kyungshin High School - May 8. Seocho High School - May 29. Seo-oon Middle School - Sep 4. Chil-won High School - Oct 16.*2014*Sep 13, 2014 (Banpo High School). Dec 20, 2014, KFAS.