3 papers
math.CO2026
Paths with Prescribed Endpoints in Semicomplete and Locally Semicomplete Digraphs
Hanzhi Bai, Jin Yan, Jia Zhou
We study two open path problems with prescribed endpoints posed by Bang-Jensen and Gutin. The first asks for a longest -path in a semicomplete digraph. The second asks wheth…
cs.DM2026
Polynomial Algorithms for Minimum Degree Partitions in Semicomplete Digraphs
Hanzhi Bai, Jin Yan
A 2-partition of a digraph is a partition of its vertex set into two nonempty parts. Degree-constrained 2-partition problems are generally computationally difficult, even when the…
math.CO2026
New Tower-Type Lower Bounds for Hypergraph Ramsey Numbers
Hanzhi Bai, Longma Du, Xinyu Hu +2
The Ramsey number is the smallest such that any red/blue coloring of the -subsets of contains a red -set or a blue -set. For fixed and , and fo…