activity
20182025
most citedHypergraphs with many extremal configurations

7 citations · 15 across the 16 of their papers we have counts for

collaborators

21 papers

math.CO2025

A note on the minimum size of Turán systems

Xizhi Liu, Oleg Pikhurko

For positive integers , a \emph{Turán -system} is an -vertex -graph in which every set of vertices contains at least one edge. Let denote…

math.CO2025

On a hypergraph Mantel theorem

Xizhi Liu

An -graph is a triangle if there exists a positive integer such that it is isomorphic to the following -graph with three edges: \begin{align*} \left…

math.CO2025

Tiling in dense graphs

Nannan Chen, Xizhi Liu, Lin Sun +1

We determine asymptotically the two extremal constructions for the tiling problem of the -shaped tree. In particular, the first extremal construction is close to the complement…

math.CO2025

Density Hajnal--Szemerédi theorem for cliques of size four

Jianfeng Hou, Caiyun Hu, Xizhi Liu +1

The celebrated Corrádi--Hajnal Theorem~\cite{CH63} and the Hajnal--Szemerédi Theorem~\cite{HS70} determined the exact minimum degree thresholds for a graph on vertices to conta…

math.CO2024

Generalized Andrásfai--Erdős--Sós theorems for odd cycles

Zian Chen, Jianfeng Hou, Caiyun Hu +1

In this note, we establish Andrásfai--Erdős--Sós-type stability theorems for two generalized Turán problems involving odd cycles, both of which are extensions of the Erdős Pentagon…

math.CO2024

Uniquely colorable hypergraphs

Xizhi Liu, Jie Ma, Tianhen Wang +1

An -uniform hypergraph is uniquely -colorable if there exists exactly one partition of its vertex set into parts such that every edge contains at most one vertex from eac…