Associate Professor
Institute of Systems and Information Engineering
Email: liutx@sk.tsukuba.ac.jp
[December 18, 2025] New preprint "Facial reduction for nice (and non-nice) convex programs".
[November 27, 2025] New preprint "A nonmonotone extrapolated proximal gradient-subgradient algorithm beyond global Lipschitz gradient continuity".
[April 25, 2025] New preprint "On the equivalence of a Hessian-free inequality and Lipschitz continuous Hessian".
I received my Bachelor degree in July 2010 from Wuhan University, School of Mathematics and Statistics. I got my PhD degree in Computational Mathematics in July 2015 from Chinese Academy of Sciences, Academy of Mathematics and Systems Science, under the supervision of Professor Yu-Hong Dai. I was a Postdoctoral Fellow in Department of Applied Mathematics at The Hong Kong Polytechnic University from March 2016 to August 2018, under the mentorship of Professor Ting Kei Pong. I was a Postdoctoral Researcher from September 2018 to March 2021 in RIKEN AIP Center hosted by Professor Akiko Takeda. I was an assistant professor at Tokyo Institute of Technology from April 2021 to April 2025. I am currently an associate professor at University of Tsukuba.
This is my CV.
Nonconvex optimization: algorithm and analysis
Ying Lin, Tianxiang Liu and Bruno F. Lourenço. Facial reduction for nice (and non-nice) convex programs.
Lei Yang, Jingjing Hu and Tianxiang Liu. A nonmonotone extrapolated proximal gradient-subgradient algorithm beyond global Lipschitz gradient continuity.
Radu I. Boţ, Minh N. Dao, Tianxiang Liu, Bruno F. Lourenço and Naoki Marumo. On the equivalence of a Hessian-free inequality and Lipschitz continuous Hessian.
Tianxiang Liu and Bruno F. Lourenço. Concrete convergence rates for common fixed point problems under Karamata regularity.
Charles Namchaisiri, Tianxiang Liu and Makoto Yamashita. A new dual spectral projected gradient method for log-determinant semidefinite programming with hidden clustering structures. Comput. Optim. Appl. 92, pp. 589-615, 2025.92, pages 589–615 92, pages 589–615
Tianxiang Liu and Bruno F. Lourenço. Convergence analysis under consistent error bounds. Found. Comput. Math. 24, pp. 429-479, 2024.
Tianxiang Liu, Ting Kei Pong and Akiko Takeda. Doubly majorized algorithm for sparsity-inducing optimization problems with regularizer-compatible constraints. Comput. Optim. Appl. 86, pp. 521-553, 2023. [code]
Tianxiang Liu and Akiko Takeda. An inexact successive quadratic approximation method for a class of difference-of-convex optimization problems. Comput. Optim. Appl. 82, pp. 141-173, 2022. [code]
Tianxiang Liu, Ivan Markovsky, Ting Kei Pong and Akiko Takeda. A hybrid penalty method for a class of optimization problems with multiple rank constraints. SIAM J. Matrix Anal. A. 41, pp. 1260-1283, 2020. [code]
Ivan Markovsky, Tianxiang Liu and Akiko Takeda. Data-driven structured noise filtering via common dynamics estimation. IEEE Trans. Signal Process, 68, pp. 3064-3073, 2020.
Tianxiang Liu, Zhaosong Lu, Xiaojun Chen and Yu-Hong Dai. An exact penalty method for semidefinite-box constrained low-rank matrix optimization problems. IMA J. Numer. Anal. 40, pp. 563-586, 2020.
Tianxiang Liu, Ting Kei Pong and Akiko Takeda. A refined convergence analysis of pDCAe with applications to simultaneous sparse recovery and outlier detection. Comput. Optim. Appl. 73, pp. 69-100, 2019.
Tianxiang Liu, Ting Kei Pong and Akiko Takeda. A successive difference-of-convex approximation method for a class of nonconvex nonsmooth optimization problems. Math. Program. 176, pp. 339–367, 2019.
Guoyin Li, Tianxiang Liu and Ting Kei Pong. Peaceman-Rachford splitting for a class of nonconvex optimization problems. Comput. Optim. Appl. 68, pp. 407-436, 2017.
Tianxiang Liu and Ting Kei Pong. Further properties of the forward-backward envelope with applications to difference-of-convex programming. Comput. Optim. Appl. 67, pp. 489-520, 2017.
RAMP2023. エラーバウンド, 正則変動及び明示的な収束率 , 東京, 2023年11月20-21日.
日本OR学会2021年秋季研究発表会. DC問題に対する非厳密Newton型近接勾配法, 東京 (zoom), 2021年9月16日-17日.
OP21. Convergence analysis under consistent error bounds, Online (zoom), July 20-23, 2021.
日本OR学会2021年春季研究発表会. 穏当なエラーバウンドと収束解析, 東京 (zoom), 2021年3月2日-3日.
ICCOPT2019. A successive difference-of-convex approximation method with applications to control problems, Berlin, August 3-8, 2019.
EURO2018. A successive difference-of-convex approximation method for a class of nonconvex nonsmooth optimization problems, Valencia, July 8-11, 2018.
ISMP2018. A successive difference-of-convex approximation method for a class of nonconvex nonsmooth optimization problems, Bordeaux, July 1-6, 2018.
SIAM-ALA18. An exact penalty method for semidefinite-box constrained low-rank matrix optimization problems, Hong Kong, May 4-8, 2018.
OP17. Further properties of the forward-backward envelope with applications to difference-of-convex programming, Vancouver, May 22-25, 2017.
June 2014 - June 2015, The Hong Kong Polytechnic University, hosted by Professor Xiaojun Chen.
My link in Google Scholar.