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.

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.