## Beomjun Choi ( 최범준 )

Email: cbj5212@gmail.com bchoi@postech.ac.kr

Research Interests

Geometric analysis: differential geometry, PDE, calculus of variation and gradient flow

Employment

Assistant professor at POSTECH, South Korea (2021.07 - )

CMC fellow at Korea Institute for Advanced Study, South Korea (2021.05 - 2021.06)

Postdoctoral research fellow at University of Toronto, Canada (2019.08 - 2021.04)

Education

PhD in Mathematics, Columbia University, New York, USA (2011.09 - 2019.05)

- Adviser: Panagiota Daskalopoulos

- Military leave of absence (2013.06- 2016.08)

BS in Mathematical Science, KAIST, Daejeon, South Korea (2007.02 - 2011.02)

- Summa Cum Laude

Publications/accepted for publication

Uniqueness of ancient solutions to Gauss curvature flow asymptotic to a cylinder, with K. Choi and P. Daskalopoulos,

to appear in J. Diff. Geom. [journal][arXiv]Asymptotics near extinction for nonlinear fast diffusion on a bounded domain, with R. McCann and C. Seis,

Arch. Ration. Mech. Anal. (ARMA) (2023) [journal][arXiv]A note on blowup limits in 3d Ricci flow, with R. Haslhofer,

Math. Res. Lett. (2023) [journal][arXiv]Hitting estimates on Einstein manifolds and applications, with R. Haslhofer,

J. reine angew. Math. (Crelle's journal).(2022) [journal][arXiv]Inverse mean curvature flow with singularities, with P.-K. Hung,

IMRN (2022) [journal][arXiv]Convergence of Gauss curvature flows to translating solitons, with K. Choi and P. Daskalopoulos,

Adv. Math. (2022) [journal][arXiv]Heat flow on time-dependent manifolds, with J. Gao, R. Haslhofer, and D. Sigal,

J. Geom. Anal. (2022) [journal][arXiv]Evolution of non-compact hypersurfaces by inverse mean curvature, with P. Daskalopoulos,

Duke Math. J. (2021) [journal][arXiv]Convergence of Curve Shortening Flow to Translating Soliton, with K. Choi and P. Daskalopoulos,

Amer. J. Math.(2021) [journal][arXiv]Type II singularities on complete non-compact Yamabe flow, with P. Daskalopoulos and J. King,

J. reine angew. Math. (Crelle's journal).(2021) [journal][arXiv]A note on the selfsimilarity of limit flows, with R. Haslhofer and O. Hershkovits,

Proc. Amer. Math. Soc.(2021) [journal][arXiv]Diffusion of biological organisms; Fickian and Fokker-Planck type diffusions, with Y.-J. Kim,

SIAM J. Appl. Math.(2019) [journal]Yamabe flow: steady solitons and type II singularities, with P. Daskalopoulos,

Nonlinear Anal.(2018) [journal][arXiv]

Preprints

Continuous family of surfaces translating by powers of Gauss curvature, with K. Choi and S. Kim. (2024)

- a part of this result was shown in the 2021 preprint by the same authors.Finite-dimensional leading order dynamics for the fast diffusion equation near extinction, with C. Seis. (2023)

Asymptotics for slowly converging evolution equations, with P.-K. Hung. (2023)

Classification of bubble-sheet ovals in R^4, with P. Daskalopoulos, W. Du, R. Haslhofer, and N. Sesum. (2022)

On existence of hypersurfaces translating by powers of Gauss curvature. (2022)

Ricci limit flows and weak solutions, with R. Haslhofer. (2021)

Translating surfaces under flows by sub-affine-critical powers of Gauss curvature, with K. Choi and S. Kim. (2021)

Multi-D fast diffusion equation via diffusive scaling of generalized Carleman kinetic equation, with K.-A. Lee. (2015)

Grants, honors, and awards

Y-KAST member, Korean Academy of Science and Technology (2023-)

Samsung Science and Technology Foundation Grant P.I. (2023-)

NRF Science Research Center CM2LA Participating Researcher (RS-2023-00219980) (2023-)

National Research Foundation of Korea (NRF-2022R1C1C1013511) (2022-2027)

KIAS associate member (2022-)

Sangsan Young Mathematician Award, Korean Mathematical Society (2021)

POSCO Science Fellow, TJ Park Foundation (2022-2023)

Basic Science Research Institute, POSTECH (NRF-2021R1A6A1A10042944) (2021-2022)

Columbia Faculty Fellow, Columbia University (2011-2019)

Samsung Scholarship for doctoral study, Samsung Scholarship Foundation (2011- 2019)

Presidential Science Scholarship from the Korean President, Korea Student Aid Foundation (2007 - 2011)

Notes

Parabolic Krylov-Safonov Harnack Inequality

- This is based on a talk I gave in graduate student geometric analysis seminar, Columbia University, Fall 2017. Most of the proof ideas and outlines are from the note of former colleague M. Connor.

Teaching

Instructor

- MATH 517 Partial Differential Equations (Fall 2023)

- MATH647 Nonlinear Partial Differential Equations (Spring 2023)

- MATH520 Differentiable Manifolds (Spring 2022)

- MATH203 Applied Linear Algebra (Fall 2021)

- MAT235 Calculus II (2020 - 2021)

- MAT235 Calculus II (2019 - 2020)

- Calculus II (Spring 2019)

- Calculus I (Spring 2017)

Teaching Assistant

- Ordinary Differential Equations (Fall 2018)

- Analysis and Optimization (Spring 2018)

- Modern Analysis I (Fall 2017)

- Ordinary Differential Equations (Fall 2016)

- Ordinary Differential Equations (Spring 2013)

- Introduction to Mathematical Finance (Fall 2012)

- Calculus II (Summer 2012)

- Modern Analysis II (Summer 2012)