Zhen He

activity

20222026

most citedExtremal results for graphs avoiding a rainbow subgraph

2 citations · 4 across the 11 of their papers we have counts for

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Showing 2022Show all

7 papers · 1 filter

math.CO2022

The maximum number of cliques in graphs with bounded odd circumference

Zequn Lv, Ervin Győri, Zhen He +3

In this work, we give the sharp upper bound for the number of cliques in graphs with bounded odd circumferences. This generalized Turán-type result is an extension of the celebrate…

math.CO2022★ 1 cited

Edges not covered by monochromatic bipartite graphs

Xiutao Zhu, Ervin Győri, Zhen He +4

Let $f_{k} (n, H)$ denote the maximum number of edges not contained in any monochromatic copy of~ $H$ in a $k$ -coloring of the edges of $K_{n}$ , and let $e x (n, H)$ denote the Turán number…

math.CO2022

Generalized Turan number for the edge blow-up graph

Zequn Lv, Ervin Győri, Zhen He +4

Let $H$ be a graph and $p$ be an integer. The edge blow-up $H^{p}$ of $H$ is the graph obtained from replacing each edge in $H$ by a copy of $K_{p}$ where the new vertices of the cliqu…

math.CO2022

Exact results for generalized extremal problems forbidding an even cycle

Ervin Győri, Zhen He, Zequn Lv +4

We determine the maximum number of copies of $K_{s, s}$ in a $C_{2 s + 2}$ -free $n$ -vertex graph for all integers $s \geq 2$ and sufficiently large $n$ . Moreover, for $s \in {2, 3}$ and…

math.CO2022★ 1 cited

Stability version of Dirac's theorem and its applications for generalized Turán problems

Xiutao Zhu, Ervin Győri, Zhen He +3

In 1952, Dirac proved that every $2$ -connected $n$ -vertex graph with the minimum degree $k + 1$ contains a cycle of length at least $min {n, 2 (k + 1)}$ . Here we obtain a stability ve…

math.CO2022

The maximum number of copies of an even cycle in a planar graph

Zequn Lv, Ervin Győri, Zhen He +3

We resolve a conjecture of Cox and Martin by determining asymptotically for every $k \geq 2$ the maximum number of copies of $C_{2 k}$ in an $n$ -vertex planar graph.

math.CO2022★ 2 cited

Extremal results for graphs avoiding a rainbow subgraph

Peter Frankl, Ervin Győri, Zhen He +5

We say that $k$ graphs $G_{1}, G_{2}, \dots, G_{k}$ on a common vertex set of size $n$ contain a rainbow copy of a graph $H$ if their union contains a copy of $H$ with each edge belonging t…