About me
I am an associate professor at the School of Mathematical Sciences, Hebei Normal University, China. My research interests focus on Ramsey theory and extremal graph theory.
I completed my undergraduate studies at Northwestern Polytechnical University. Both my master’s and Ph.D. studies were conducted at Nanjing University under the guidance of Professor Yaojun Chen. Meanwhile, my Ph.D. studies also took place at the University of Twente (The Netherlands), where I was advised by Professor Hajo Broersma.
Feel free to contact me at ybzhang(at)hebtu.edu.cn, and I am happy to serve as a reviewer for manuscripts in Ramsey theory and extremal graph theory.
Papers accepted
- Ramsey numbers of cycles versus multiple odd wheels,
with Zhaofa Wang,
Bulletin of the Australian Mathematical Society, published online. - Ramsey numbers of generalized fans versus multiple cliques,
with Ze Wang,
Applied Mathematics and Computation, accepted.
Papers in 2026
- Ramsey goodness of fans,
with Yaojun Chen,
Discrete Mathematics 349(2) (2026), Art. no. 114771. - On tree-wheel Ramsey numbers,
with Yaojun Chen and Yunqing Zhang,
Discrete Applied Mathematics 383 (2026), 80–84. - Ramsey numbers of trees versus generalized wheels,
with Yaojun Chen and Yunqing Zhang,
Discrete Mathematics 349(4) (2026), Art. no. 114938. - Star-critical Ramsey numbers of cycles revisited,
with Yang Sun,
Discussiones Mathematicae Graph Theory 46(1) (2026), 225–235. - Ramsey numbers of small wheels versus fans,
with Haiyu Zeng and Feng Zhao,
Bulletin of the Malaysian Mathematical Sciences Society 49(1) (2026), Art. no. 1. - The inverted weak Schur numbers,
with Haiyu Zeng and Yuehua Zeng,
Discrete Mathematics, Algorithms and Applications 18(1) (2026), Art. no. 2550024.
Papers in 2025
- Online Ramsey numbers of $K_{1,3}$ versus paths,
with Ruyu Song and Sha Wang,
Discrete Applied Mathematics 377 (2025), 218–224. - Ramsey goodness of stars and fans for the Hajós graph,
with Jiafu He and Haiyu Zeng,
Discrete Mathematics & Theoretical Computer Science 27(3) (2025), Art. no. 11. - Weakened size Gallai-Ramsey numbers for $K_5$,
with Ze Wang,
Bulletin of the Iranian Mathematical Society 51 (2025), Art. no. 72. - Ramsey numbers of cycles versus multiple wheels,
with Zhaofa Wang,
Filomat 39(33) (2025), 11961–11967. - Matching-star size Ramsey numbers under connectivity constraint,
with Fanghua Guo and Yunqing Zhang,
Journal of Combinatorial Mathematics and Combinatorial Computing 126 (2025), 93–100. - Connected size Ramsey numbers of matchings versus a small path or cycle,
with Sha Wang, Ruyu Song, and Yixin Zhang,
Electronic Journal of Graph Theory and Applications 13(1) (2025), 163–170. - Star-quadrilateral Ramsey number and beyond,
with Yaojun Chen and Xuemei Zhang,
Advances in Mathematics (China) 54(2) (2025), 292–314.
Earlier papers
- The Ramsey number of a long even cycle versus a star,
with Peter Allen, Tomasz Łuczak, and Joanna Polcyn,
Journal of Combinatorial Theory, Series B 162 (2023), 144–153. - A proof of a conjecture on matching-path connected size Ramsey number,
with Yixin Zhang and Hexuan Zhi,
AIMS Mathematics 8(4) (2023), 8027–8033. - Online and connected online Ramsey numbers of a matching versus a path,
with Ruyu Song,
Symmetry 14(11) (2022), Art. no. 2277. - Quadrilateral-tree planar Ramsey numbers,
with Xiaolan Hu and Yunqing Zhang,
Bulletin of the Australian Mathematical Society 97 (2018), 194–199. - The Ramsey numbers of wheels versus a fan of order five,
with Yanjun Meng and Yunqing Zhang,
Ars Combinatoria 137 (2018), 365–372. - Further results on the largest matching root of unicyclic graphs,
with Weijun Liu, Qiang Guo, Lihua Feng, and Ivan Gutman,
Discrete Applied Mathematics 221 (2017), 82–88. - An exact formula for all star-kipas Ramsey numbers,
with Hajo Broersma and Binlong Li,
Graphs and Combinatorics 33 (2017), 141–148. - Weakened Ramsey numbers and their hypergraph analogues,
with Mark Budden and Matthew Stender,
Integers 17 (2017), Art. no. A23. - Narrowing down the gap on cycle-star Ramsey numbers,
with Hajo Broersma and Yaojun Chen,
Journal of Combinatorics 7 (2016), 481–493. - On fan-wheel and tree-wheel Ramsey numbers,
with Hajo Broersma and Yaojun Chen,
Discrete Mathematics 339 (2016), 2284–2287. - On star-critical and upper size Ramsey numbers,
with Hajo Broersma and Yaojun Chen,
Discrete Applied Mathematics 202 (2016), 174–180. - Closing the gap on path-kipas Ramsey numbers,
with Halina Bielak, Hajo Broersma, Přemek Holub, and Binlong Li,
Electronic Journal of Combinatorics 22 (2015), P3.21. - A note on Ramsey numbers for fans,
with Hajo Broersma and Yaojun Chen,
Bulletin of the Australian Mathematical Society 92 (2015), 19–23. - All complete graph-wheel planar Ramsey numbers,
with Yaojun Chen and Guofei Zhou,
Graphs and Combinatorics 31 (2015), 2459–2465. - Three results on cycle-wheel Ramsey numbers,
with Hajo Broersma and Yaojun Chen,
Graphs and Combinatorics 31 (2015), 2467–2479. - Ramsey numbers of trees versus fans,
with Hajo Broersma and Yaojun Chen,
Discrete Mathematics 338 (2015), 994–999. - A remark on star-$C_4$ and wheel-$C_4$ Ramsey numbers,
with Hajo Broersma and Yaojun Chen,
Electronic Journal of Graph Theory and Applications 2(2) (2014), 110–114. - The Ramsey numbers of fans versus a complete graph of order five,
with Yaojun Chen,
Electronic Journal of Graph Theory and Applications 2(1) (2014), 66–69. - The Ramsey numbers of wheels versus odd cycles,
with Yaojun Chen and Yunqing Zhang,
Discrete Mathematics 323 (2014), 76–80. - Ramsey numbers for 7-cycle versus wheels with small order,
with Yunqing Zhang and Shiping Zhu,
Journal of Nanjing University (Mathematical Biquarterly) 30(1) (2013), 48–55.
Ph.D. Students
- Hexuan Zhi (expected 2028)
- Jiafu He (expected 2029)
Master’s Students
- Ruyu Song (graduated 2023)
- Sha Wang (graduated 2023)
- Yixin Zhang (graduated 2023)
- Fanghua Guo (graduated 2024)
- Yufan Li (graduated 2024)
- Ze Wang (graduated 2025)
- Haiyu Zeng (graduated 2025)
- Xiaohua Feng (expected 2026)
- Yuehua Zeng (expected 2026)
- Xiaoqian Sun (expected 2027)
- Yang Sun (expected 2027)
- Zhaofa Wang (expected 2027)