Jingjun Han

Department of Mathematics

Krieger School of Arts and Sciences 

Johns Hopkins University

3400 N. Charles Street, Baltimore, MD 21218                                                     

Office: 221 Krieger Hall

Email: jhan@math.jhu.edu

Tel: 410-516-7408

 

 

I am a J.J. Sylvester Assistant Professor in the Department of Mathematics, Johns Hopkins University. I got my Ph.D. in July 2018 from Beijing International Center for Mathematical Research, Peking University (Beijing, China), under the supervision of Prof. Gang Tian and Prof. Chenyang Xu. My undergraduate advisor is Prof. Bican Xia at Peking University.  



Homepage at Google

 

CV

 



Fall 2018 teaching: Math 401, Introduction to Abstract Algebra  



Research Interests:

Algebraic Geometry : Birational Geometry (Minimal Model Program, boundedness of varieties)

Symbolic Computation (Computer Algebra): Cylindrical Algebraic Decomposition, Polynomial Inequalities, etc.

 

I am a co-organizer (with Vyacheslav Shokurov, Xudong Zheng) of Hopkins Algebraic Geometry Seminar.

 

Publications and Preprints

1.     Jingjun Han, Wenfei Liu, On nonvanishing and abundance for generalized polarized surfaces, arXiv:1808.06361.

2.     Jingjun Han, Zhan Li, Weak Zariski decompositions and log terminal models for generalized polarized pairs, arXiv:1806.01234, submitted.

3.     Weichung Chen, Gabriele Di Cerbo, Jingjun Han, Chen Jiang, and Roberto Svaldi, Birational boundedness of rationally connected Calabi–Yau 3-folds, arXiv:1804.09127, submitted.

4.     Christopher D. Hacon, Jingjun Han. On a connectedness principle of Shokurov-Koll\'{a} r type. To appear in Science China Mathematics, arXiv:1801.01801.

5.     Jingjun Han, Zhan Li, Lu Qi. ACC for log canonical threshold polytopes, arXiv:1706.07628, submitted.

6.     Jingjun Han, Zhan Li. On Fujita's conjecture for pseudo-effective thresholds, arXiv:1705.08862, submitted.

7.     Jingjun Han. Multivariate Discriminant and Iterated Resultant. Acta Mathematica Sinica, English Series, 32: 659--667, 2016.

8.     Jingjun Han, Liyun Dai, Hoon Hong, Bican Xia. Open Weak CAD and Its Applications. Journal of Symbolic Computation, 80, 785--816, 2017.

9.     Jingjun Han, Bican Xia, Zhi Jin. Proving inequalities and solving global optimization problems via simplified CAD projection. Journal of Symbolic Computation, 72: 209--230, 2016.

10.  Jingjun Han, Liyun Dai, Bican Xia, Constructing Fewer Open Cells by GCD Computation in CAD Projection. Proceedings of the 39th International Symposium on Symbolic and Algebraic Computation. Pages 240--247, ACM, 2014.

11.   Jingjun Han, A Complete Method Based on Successive Difference Substitution Method for Deciding Positive Semi-definiteness of Polynomials, Acta Scientiarum Naturalium Universitatis Pekinensis, 2013(49): 545--551. (in Chinese)

12.  Jingjun Han, Simple Quantifier-free Formula of Positive Semidefinite Cyclic Ternary Quartic Forms, Computer Mathematics, 9th Asian Symposium (ASCM2009), Fukuoka, December 2009, 10th Asian Symposium (ASCM2012), Beijing, October 2012, Contributed Papers and Invited Talks, Ruyong Feng, Wen-shin Lee, Yosuke Sato Eds, pp 261--274, Springer, 2014.

Books and Chapters

1.     Jingjun Han, Chen Jiang. Effective birationality and special BAB, submitted to the volume of Singularities, Linear Systems and Fano Varieties (on the BAB conjecture), Caucher Birkar and Jungkai Chen (eds).

2.     An introduction to the proving of elementary inequalities (in Chinese), Harbin Institute of Technology Press, China, 2011 (2nd, 2014, 343 pp.). 


 

Software--Psdgcd, a Maple Package

A package using Maple language, which provides several functions for proving polynomial inequalities and solving global optimization problems efficiently.

Download: Psdgcdv53, User guide on Maple.

The software was developed by myself during 2009-2014. The algorithm is based on the following papers:

1.     Jingjun Han, Liyun Dai, Hoon Hong, Bican Xia. Open Weak CAD and Its Applications. Journal of Symbolic Computation, 80, 785--816, 2017.

2.     Jingjun Han, Bican Xia, Zhi Jin. Proving inequalities and solving global optimization problems via simplified CAD projection. Journal of Symbolic Computation, 72: 209--230, 2016.

3.     Jingjun Han, Liyun Dai, Bican Xia, Constructing Fewer Open Cells by GCD Computation in CAD Projection. Proceedings of the 39th International Symposium on Symbolic and Algebraic Computation. Pages 240--247, ACM, 2014.

4.     Jingjun Han, Simple Quantifier-free Formula of Positive Semidefinite Cyclic Ternary Quartic Forms, Computer Mathematics, 9th Asian Symposium (ASCM2009), Fukuoka, December 2009, 10th Asian Symposium (ASCM2012), Beijing, October 2012, Contributed Papers and Invited Talks, Ruyong Feng, Wen-shin Lee, Yosuke Sato Eds, pp 261--274, Springer, 2014.