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Yunhyung Cho
Associate professor,
Seoul, Republic of Korea.
(E-mail : yunhyung_at_skku_dot_edu )
Education
Ph.D. in Mathematics (2010. 8), KAIST.
Thesis title : Circle actions on symplectic manifolds (Advisor : Dong Youp Suh).
B.S. in Mathematics (2004. 2), KAIST.
Employment
2023. 3 - Associate Professor (tenured), Sungkyunkwan University (South Korea).
2021. 3 - 2023. 2 : Associate Professor, Sungkyunkwan University (South Korea).
2017. 3 - 2021. 2: Assistant Professor, Sungkyunkwan University (South Korea).
2015. 10 - 2017. 2 : Research Fellow (supervisor : Yong-Geun Oh), IBS-CGP (South Korea).
2014. 9 - 2015. 9 : Research Fellow (supervisor : Leonor Godinho), IST Lisbon (Portugal).
2012. 9 - 2012. 12 : Visiting scholar (host : Dusa McDuff), Columbia University (USA).
2011. 9 - 2014. 9 : Research Fellow (supervisor : Bumsig Kim), KIAS (South Korea).
2010. 9 - 2011. 8 : Research Fellow (supervisor : Dong Youp Suh), KAIST (South Korea).
Research interest : Compact Lie group actions and Symplectic geometry
Hamiltonian action
Mirror Symmetry
Newton-Okounkov body
Completely integrable system
Published or accepted articles
Log-concavity of complexity one Hamiltonian torus actions (with Min Kyu Kim)
C. R. Math. Acad. Sci. Paris. 350 (2012), No.17-18, 845-848.
Proc. Amer. Math. Soc. 142 (2014), No. 7, 2417-2428.
Math. Res. Lett. 21 (2014), No. 4, 691-696.
Semifree Hamiltonian circle actions on 6-dimensional symplectic manifolds with non-isolated fixed point set (with Taekgyu Hwang and Dong Youp Suh)
J. Symplectic Geom. 13 (2015), No. 4, 963-1000.
5. Unimodality of Betti numbers for Hamiltonian circle actions with index-increasing moment maps
Internat. J. Math. 27 (2016), No. 5, 1650043 (14 pages).
6. Hard Lefschetz property of symplectic structures on compact Kaehler manifolds
Trans. Amer. Math. Soc. 368 (2016), No. 11, 8223-8248.
7. Hamiltonian circle action with self-indexing moment map (with Min Kyu Kim)
Math. Res. Lett. 23 (2016), No. 3, 719-732.
8. Embedded surfaces for symplectic circle actions (with Min Kyu Kim and Dong Youp Suh)
Chin. Ann. Math. Ser. B 38 (2017), No. 6, 1197-1212. (Proceedings of the International Open Chinese-Russian Conference)
9. On the f-vectors of Gelfand-Cetlin polytopes (with Byung Hee An and Jang Soo Kim )
European J. Combin. 67 (2018), 61-77.
10. Hard Lefschetz property for Hamiltonian torus actions on 6-dimensional GKM-manifolds (with Min Kyu Kim)
J. Symplectic Geom. 16 (2018), No. 6, 1549-1590.
11. On the Chern numbers for pseudo-free circle actions (with Byung Hee An )
J. Symplectic Geom. 17 (2019), No. 1, 1-40.
12. Classification of six dimensional monotone symplectic manifolds admitting semifree circle actions I
Internat. J. Math. 30 (2019), No. 6, 1950032 (71 pages).
13. Monotone Lagrangians in flag varieties (with Yoosik Kim )
Int. Math. Res. Not. IMRN. (2021), No. 18, 13892-13945. published online
14. Lagrangian fibers of Gelfand-Cetlin systems of SO(n)-type (with Yoosik Kim )
Transform. Groups 25 (2020) 1063-1102.
15. Lagrangian fibers of Gelfand-Cetlin systems (with Yoosik Kim and Yong-Geun Oh )
Adv. Math. 372 (2020) 107304 (57pp).
16. A critical point analysis of Landau--Ginzburg potentials with bulk in Gelfand--Cetlin systems (with Yoosik Kim and Yong-Geun Oh )
Kyoto J. Math. 61 (2021), No. 2, 259-304. (Proceedings of the conference in honor of Kenji Fukaya's 60th birthday)
17. Classification of six dimensional monotone symplectic manifolds admitting semifree circle actions II
Internat. J. Math. 32 (2021), No. 2, 2050120 (47 pages).
Internat. J. Math. 32 (2021), No. 2, 2050106 (58 pages).
19. Remark on the Betti numbers for Hamiltonian circle actions
C. R. Math. Acad. Sci. Paris. 359 (2021), No. 2, 113-117.
20. On the combinatorics of string polytopes (with Yoosik Kim , Eunjeong Lee , and Kyeong-Dong Park)
J. Comb. Theory Ser. A 184 (2021), 105508 (46pp)
21. Enumeration of Gelfand-Cetlin type reduced words (with Jang Soo Kim and Eunjeong Lee )
Electron. J. Comb. 29 (2022), No. 1, 1-27.
22. Small resolutions of toric varieties associated to string polytopes of small indices (with Yoosik Kim , Eunjeong Lee , and Kyeong-Dong Park)
Commun. Contemp. Math. 25 (2023), No.1, 2150112 (56 pages)
23. On the enumeration of Fano Bott manifolds (with Eunjeong Lee , Mikiya Masuda, and Seonjeong Park )
to appear in The Fields Institute Communication Volume: Toric Topology and Polyhedral Products.
24. Unique toric structure on a Fano Bott manifold (with Eunjeong Lee , Mikiya Masuda, and Seonjeong Park )
J. Symplectic Geom. 21 (2023), No. 3, 439-462.
25. c_1-cohomological rigidity for smooth Fano toric varieties of Picard number two (with Eunjeong Lee , Mikiya Masuda, and Seonjeong Park )
to appear in Proc. Steklov Inst. Math. (Proceedings of the conference in honor of Victor Buchstaber's 80th birthday)
26.Newton–Okounkov polytopes of type A flag varieties of small ranks arising from cluster structures (with Naoki Fujita, Akihiro Higashitani, and Eunjeong Lee )
to appear in Proc. Steklov Inst. Math. (Proceedings of the conference in honor of Victor Buchstaber's 80th birthday)
Articles submitted or under revision
Classification of six dimensional monotone symplectic manifolds admitting semifree circle actions (Complete version)
On combinatorics of string polytopes of types B and C (with Naoki Fujita and Eunjeong Lee)
Cluster algebras and monotone Lagrangian tori (with Myungho Kim, Yoosik Kim, and Euiyong Park)
In preparation
Maximal tori in Hamiltonian diffeomorphism groups and their mutations
Lecture Video
Lectures on equivariant symplectic geometry. [link]
Conferences and Seminars 2017-2023
(* : attend , * : talk )
(Seoul, Korea)* Mirror symmetry, tropical geometry, Gelfand-Kapranov-Zelevinsky A-philosophy and beyond (2017/02/27 - 2017/03/03) [website]
(Barcelona, Spain)* Finite Dimensional Integrable Systems in Geometry and Mathematical Physics (FDIS 2017) (2017/07/03 - 2017/07/07) [website]
(Pohang, Korea)* Pacific Rim Complex-Symplectic Geometry Conference (2017/07/31 - 2017/08/04) [website]
(Beijing, China)* Second BICMR & IBS-CGP Joint Symplectic Geometry Workshop (2017/09/18 - 2017/09/22) [website]
(Sichuan, China)* East Asian Symplectic Conference 2017 (2017/10/29 - 2017/11/04) [website]
(Seoul, Korea)* KIAS [AG-CA] Seminar (2017/11/27) [website]
(Jeonju, Korea)* 2017 Pohang Mathematics Workshop (2017/12/08 - 2017/12/10) [website]
(Da Nang, Vietnam)* Singularities and Algebraic Geometry (2018/01/08 - 2018/01/13) [ website]
(Boston, U.S.)* Visiting, Boston University (2018/02/05 - 2018/02/14) [ website]
(Padova, Italy) Recent Advances in Hamiltonian Dynamics and Symplectic Topology (2018/02/12 - 2018/02/16) [website]
(Bad Honnef, Germany) Geometry and Representation Theory of Algebraic Groups (2018/03/05 - 2018/03/10) [website]
(Seoul, Korea)* 2018 KMS Spring Meeting (2018/04/20 - 2018/04/21) [website]
(Tel Aviv, Israel) Topological data analysis meets symplectic topology (2018/04/29 - 2018/05/03) [website]
(Sendai, Japan)* JCCA 2018 (2018/05/20 - 2018/05/24) [website]
(NIMS, Korea) CIMPA-NIMS Research School on symplectic embeddings, systolic inequalities and celestial mechanics (2018/6/11 - 2018/6/20) [website]
(CUHK, Hong Kong)* Visiting, Chinese University of Hong Kong (2018/6/24 - 2018/6/29)
(Kanagawa, Japan)* HAYAMA Symposium on Complex Analysis in Several Variables XX and Pacific Rim Complex-Symplectic Geometry Conference (2018/7/13 - 2018/7/17) [website]
(Toronto, Canada)* Poisson 2018 (2018/07/16 - 2018/07/20) [website]
(Boston, U.S.)* Visiting, Boston University (2018/7/22 - 2018/8/21)
(Rio, Brazil) ICM 2018 (2018/08/01 - 2018/08/09) [website]
(Bochum, Germany) Geometry and representation theory at the interface of Lie algebras and quivers (2018/09/10 - 2018/09/14) [website]
(COEX, Korea)* KMS-DMV Joint Conference (2018/10/03 - 2018/10/06) [website]
(KIAS, Korea)* Matrix Factorizations and Mirror Symmetry (2018/10/15 - 2018/10/19) [website]
(Pohang, Korea)* Wall-crossing formula, open Gromov-Witten invariants and related areas (2018/10/29 - 2018/10/31) [website]
(Seoul, Korea)* SWAG 5 (2018/12/07) [website]
(Jeju, Korea)* Conference of Geometry and Representations (2019/01/07 - 2019/01/11) [website]
(Busan, Korea)* Winter School on Poisson Structures in Algebraic Geometry (2019/01/15 - 2019/01/17) [website]
(Gyeongju, Korea)* The 5-th Korea Toric Topology Winter Workshop (2019/01/21 - 2018/01/23) [website]
(Miami, U.S.) Mirror Symmetry and Related Topics (2019/01/28 - 2019/02/02) [website]
(Suwon, Korea)* Seminar at Ajou University (2019/02/11) [website]
(Kyoto, Japan)* Geometry and Everything, Fukaya 60th Birthday Conference (2019/02/17 - 2019/02/22) [website]
(Cambridge, UK)* Categorical Symplectic Topology Conference (2019/03/25 - 2019/03/29) [website]
(KIAS, Korea)* Seminar at KIAS (2019/04/12)
(KIAS, Korea)* Seminar at KIAS (2019/06/14)
(Montreal, Canada) Current Trends in Symplectic Topology (2019/07/01 - 2019/07/12) [website]
(Cologne, Germany) Quantization in Symplectic Geometry (2019/07/15 - 2019/07/19) [website]
(Toronto, Canada) Graduate Summer School on Homological Algebra of Mirror Symmetry (2019/07/22 - 2019/08/02) [website]
(Toronto, Canada) New Structures in Algebraic Geometry and their Symplectic Interpretations (2019/08/06 - 2019/08/09) [website]
(Toronto, Canada) The Geometry and Algebras of Landau-Ginzburg Models (2019/09/16 - 2019/09/20) [website]
(KIAS, Korea)* The 4th KIAS Alumni Workshop in Mathematics (2019/09/20) [website]
(NCTS, Taiwan) East Asian Symplectic Conference 2019 (2019/09/26 - 2019/10/01) [website]
(Pusan National University, Korea)* Colloquium (2019/10/17)
(Hongik Univ., Korea)* 2019 KMS Annual Meeting (2019/10/25 - 2019/10/27) [website]
(SNU, Korea)* Colloquium (2019/11/14)
(Okayama, Japan)* Toric topology 2019 (2019/11/18 - 2019/11/21) [website]
(Jeju, Korea)* Pohang Mathematics Workshop 2019 (2019/12/5 - 2019/12/8) [website]
(Osaka, Japan)* Visiting (Osaka Prefecture Univ. and Osaka City Univ.) (2019/12/26 - 2020/1/5)
(Pusan, Korea)* Winter school on Spherical varieties (2020/1/7 - 2020/1/9) [website]
(KIAS, Korea)* Combinatorics of flag varieties and related topics (2020/1/15 - 2020/1/17) [website]
(Yeosu, Korea)* SNU-SSWU Joint Topology Workshop (2020/1/30 - 2020/2/1) [website]
(Osaka, Japan)* Visiting, Osaka City University (2020/2/3 - 2020/2/17)
(Pusan, Korea) 2020 기하학 심포지엄 (The conference is postponed until further notice)
(Toronto, Canada) Workshop on torus actions in Topology (The conference is postponed until further notice)
(Hangzhou, China) Hangzhou Workshop on Symplectic Topology (The conference is postponed until further notice)
(Minnesota, U.S.) Open problems on algebraic combinatorics (The conference is postponed until further notice)
(Osaka, Japan)* Osaka Combinatorics Seminar (2020/6/6, online) [website]
(KIAS, Korea)* Seminar talk(2020/09/14, online)
(IBS-CGP, Korea)* Legendrians, cluster algebras, and mirror symmetry (four lectures) (2021/01/04, 2021/01/05, online) [website]
(Sogang University, Korea)* Topology seminar (2021/01/22, online) [website]
(Ajou University, Korea)* Combinatorics on flag varieties and related topics (2021/01/25, online) [website]
(Okayama, Japan)* Toric topology 2021 (2021/03/24, online) [website]
(Kumamoto, Japan)* 2021 Korea-Japan Joint Mathematical Meeting (2021/09/13, online) [website]
(Jeju, Korea)* Symplectic Geometry and Beyond, Part I (2022/02/07) [website]
(KAIST, Korea)* Seminar talk (2022/06/13)
(KAIST, Korea)* 6th Korea Toric Topology Workshop (2022/07/11) [website]
(Pyungchang, Korea)* 2022 SNU-SSWU Topology Workshop (2022/08/19) [website]
(Kumamoto, Japan)* Toric degenerations and Mirror symmetry in Kumamoto (2022/10/13) [website]
(IST Lisbon, Portugal)* Geometria em Lisboa Seminar (2023/01/19) [website]
(IBSCCG, Korea)* Complex geometry seminar (2023/03/02) [website]
(Pusan National University, Korea)* PNU Geometry and Topology seminar (2023/05/08) [website]
(RIMS, Japan)* Geometry and Topology of Transformation groups (2023/06/14) [website]
(Chungbuk National University, Korea)* Algebraic Geometry and Topology Workshop (2023/07/12) [website]
(Osaka Metropolitan University, Japan)* TGTC 2023 (2023/08/07 ~ 2023/08/10 ) [website]
(Pusan National University, Korea)* 2023 Summer seminars on Geometry and Topology at PNU (2023/08/31 ~ 2023/09/02 ) [website]
(SNU, Korea)* 2023 KMS annual meeting (2023/10/26 ~ 2023/10/28 ) [website]
(KNU, Korea)* Lectures on Toric geoemtry (10 lectures) (2023/10/16 - 2023/12/27) [website]
(GNU, Korea)* Unique toric structures on Fano manifolds (2024/02/14 - 2024/02/17) [website]
(KNU, Korea)* The 7th Workshop for Young Symplectic Geometers (2024/02/23 - 2024/02/25) [website]
(KIAS, Korea)* The 30th KIAS Combinatorics Workshop (2024/03/08 - 2024/03/09) [website]