Personal Information
First name: Jong In
Last name: Han
Email: jihan09@kias.re.kr
Nationality: South Korea
Education
B.S., Mathematical Sciences, KAIST, 2015
M.S., Mathematical Sciences, KAIST, 2018 (Advisor: Sijong Kwak)
Ph.D., Mathematical Sciences, KAIST, 2025 (Advisor: Sijong Kwak)
Positions
KIAS (Korea Institute For Advanced Study), Research fellow, 2025.03-
Research Interest
Algebraic Geometry (syzygies, higher secant varieties, tangential varieties);
Applied Algebraic Geometry (tensors, sum of squares)
Papers and Preprints
Jong In Han, Jeong-Hoon Ju, and Yeongrak Kim, Recursive Koszul flattenings of determinant and permanent tensors, preprint, arXiv:2503.12032, submitted.
Jong In Han and Sijong Kwak, Surface counterexamples to the Eisenbud-Goto regularity conjecture, Trans. Amer. Math. Soc. 377 (2024), 5561-5581.
Jong In Han, Sijong Kwak, and Euisung Park, Characterization of projective varieties beyond varieties of minimal degree and del Pezzo varieties, J. Algebra 636 (2023), 732-756.
Ongoing Works
Jong In Han, Jeong-Hoon Ju, and Yeongrak Kim, Border rank of the 4 × 4 determinant tensor is twelve, ongoing work.
Junho Choe, Jong In Han, and Sijong Kwak, Classification of higher secant varieties of minimal degree of classical varieties, ongoing work.
Jong In Han, Sijong Kwak, and Wanseok Lee, Hierarchy on graded Betti numbers and Castelnuovo theory of syzygies, ongoing work.
Jong In Han, Jaewoo Jung, and Euisung Park, On quadratic persistence of some projective varieties and its applications, ongoing work.
Jong In Han and Sijong Kwak, On the locus of d-secant lines, ongoing work.
Talks
Recursive Koszul flattenings of determinant and permanent tensors, KIAS HCMC Algebraic Geometry Seminar, Seoul, South Korea, 2025.05.07.
Hierarchy on graded Betti numbers and Castelnuovo theory of syzygies, 2025 WORKSHOP on Projective Algebraic Geometry and Commutative Algebra, Busan, South Korea, 2025.04.11.
Some open problems in syzygies and related topics, PNU Geometry and Topology seminar, Busan, South Korea, 2025.04.07.
Higher secant varieties of curves of minimal degree and del Pezzo curves, Algebraic Geometry Seminar in Kumamoto, Kumamoto, Japan, 2024.08.08.
Surface counterexamples to the Eisenbud-Goto conjecture, Algebraic Geometry Seminar in Kumamoto, Kumamoto, Japan, 2024.08.06.
Recursive Koszul flattenings of determinant and permanent tensors, JM Invariant at 60: A Conference on Tensor Invariants in Geometry and Complexity Theory, Auburn, AL, USA, 2024.05.14.
Methods to decompose tensors, Mini-Workshop on Algebra, Geometry and Applications - After SIAM-AG 2023, Daejeon, South Korea, 2023.10.05.
Characterization of projective varieties beyond varieties of minimal degree and del Pezzo varieties, Exploring Algebraic Geometry and Topology, Yangpyeong, South Korea, 2023.05.31.
Projective surfaces in P^4 that are counterexamples to the Eisenbud-Goto regularity conjecture, Current Developments in Algebra and Topology 2022 - Joint Workshop between Korea and Vietnam, Buyeo, South Korea, 2022.10.28.
Upper bounds of graded Betti numbers of projective varieties and characterizations of extremal cases, Algebraic Geometry (Castelnuovo Theory and Related Fields) Seminar, Busan, South Korea, 2022.04.13.
Posters
Surface counterexamples to the Eisenbud-Goto conjecture, 2024 KMS Spring Meeting, Daejeon, South Korea, 2024.04.19.
Counterexamples of surfaces to the Eisenbud-Goto regularity conjecture, Budding Workshop in Algebraic Geometry, Hwaseong, South Korea, 2023.03.30.
Honors and Awards
2024 KAIST Graduate Student Excellence Paper Award
2024 KMS Spring Meeting, excellent poster award
2008 Korean Mathematical Olympiad, high school session, main test, silver prize
2007 Korean Mathematical Olympiad, high school session, main test, silver prize
2006 Korean Mathematical Olympiad, middle school session, main test, gold prize
Teaching Assistant Experience (at KAIST)
2021 Fall, Modern Algebra II
2021 Spring, Modern Algebra I
2021 Spring, Calculus I
2020 Fall, Linear Algebra
2020 Fall, Calculus II
2020 Spring, Introduction to Number Theory
2020 Spring, Introduction to Linear Algebra
2019 Fall, Linear Algebra
2019 Fall, Calculus II
2019 Spring, Modern Algebra I
2019 Spring, Calculus I
2018 Fall, Modern Algebra II
2018 Spring, Modern Algebra I
2018 Spring, Introduction to Linear Algebra
2017 Fall, Introduction to Linear Algebra
2017 Spring, Complex Variables I
2017 Spring, Introduction to Linear Algebra