8 papers · 1 filter
Local versus global average degree in bipartite graphs
Jianfeng Hou, Hongbin Zhao
Let denote the maximum, over all -vertex bipartite graphs without isolated vertices, of the ratio of the minimum local average degree to the global average…
An Improved Upper Bound for Finite Sidon Sets via Vector-Valued Smoothing
Jianfeng Hou, Hongbin Zhao
Let denote the largest cardinality of a Sidon subset of . We prove \[ F(N)\le N^{1/2}+γ_0N^{1/4}+O(1), \qquad γ_0=0.94349\ldots<0.9435. \] This improves…
Turán numbers of -uniform tight even cycles minus one edge
Wanfang Chen, Jianfeng Hou, Xizhi Liu +2
For every integer and sufficiently large , we show that the extremal construction for the Turán number of the -uniform tight cycle of length minus one edge i…
On cliques in hypergraphs under bounded -norm
Jianfeng Hou, Hongbin Zhao
Let be an -uniform hypergraph. For , let be the number of edges of containing , and define the $…
Odd hypergraph Mantel theorems
Jianfeng Hou, Xizhi Liu, Yixiao Zhang +2
A classical result of Sidorenko (1989) shows that the Turán density of every -uniform hypergraph with three edges is bounded from above by . For even , this bound is tig…
Exact Turán densities in triple systems
Nannan Chen, Yuzhen Qi, Caihong Yang +1
In this paper, we prove several new Turán density results for -graphs. We show: , ,…
Turán density of tight cycles minus one edge in the -norm
Levente Bodnár, Jinghua Deng, Jianfeng Hou +2
The -uniform tight -cycle minus one edge is the -graph on vertices consisting of consecutive triples in the cyclic order. We show that f…
A criterion for Andrásfai--Erdős--Sós type theorems and applications
Jianfeng Hou, Xizhi Liu, Hongbin Zhao
The classical Andrásfai--Erdős--Sós Theorem states that for , every -vertex -free graph with minimum degree greater than must b…