Rongxing Xu

activity

20172026

most citedMapping sparse signed graphs to

(K_{2 k}, M)

3 citations · 5 across the 15 of their papers we have counts for

collaborators

18 papers

math.CO2026

On the minimum number of triangles in balanced tripartite graphs with large minimum degree

Chunqiu Fang, Rongxing Xu

Let $f (n, t)$ be the minimum number of triangles in a tripartite graph with $n$ vertices in each part and minimum degree at least $n + t$ . In 1975, Bollobás, Erdős and Szemerédi prove…

math.CO2026

On the maximum number of triangles in tripartite graphs with no $4$ -cycles between any two parts

Chunqiu Fang, Rongxing Xu

Let $G$ be a $3$ -partite graph with $k$ vertices in each part such that the bipartite graph induced by any two parts contains no cycle of length four. Fischer and Matoušek [J. Comb…

math.CO2026

Codegree Thresholds for $λ$ -Choosability of Graphs

Chunqiu Fang, Rongxing Xu

Let $λ = {k_{1}, \dots, k_{q}}$ be a partition, and let $∣ λ ∣ = k_{1} + \dots + k_{q}$ . A $∣ λ ∣$ -list assignment $L$ of a graph $G$ is a $λ$ -assignment if its color set can be partitioned into $q$ …

math.CO2026

The strong fractional choice number of triangle-free planar graphs

Xiaolan Hu, Rongxing Xu

Let $a, b$ be positive integers with $a \geq b$ . A graph $G$ is $(a, b)$ -choosable if, for every assignment of lists $L (v)$ of size $a$ to the vertices of $G$ , there exists a choice of…

math.CO2026

Degree-choosability of proper conflict-free list coloring of sparse graphs

Masaki Kashima, Riste Škrekovski, Rongxing Xu

Given a graph $G$ and a mapping $f : V (G) \to N$ , an $f$ -list assignment of $G$ is a function that maps each $v \in V (G)$ to a set of at least $f (v)$ colors. For an $f$ -list…

math.CO2025

Partitioning triangle-free planar graphs into a forest and a linear forest

Guanwu Liu, Rongxing Xu

Raspaud and Wang conjectured that every triangle-free planar graph can be vertex-partitioned into an independent set and a forest. Independently, Kawarabayashi and Thomassen also r…

math.CO2025

Remarks on proper conflict-free degree-choosability of graphs with prescribed degeneracy

Masaki Kashima, Riste Škrekovski, Rongxing Xu

A proper coloring $ϕ$ of $G$ is called a proper conflict-free coloring of $G$ if for every non-isolated vertex $v$ of $G$ , there is a color $c$ such that $∣ ϕ^{- 1} (c) \cap N_{G} (v) ∣ = 1$ …

math.CO2025

Proof of a conjecture of Voss on bridges of longest cycles

Jie Ma, Rongxing Xu

Bridges are a classical concept in structural graph theory and play a fundamental role in the study of cycles. A conjecture of Voss from 1991 asserts that if disjoint bridges $B_1,…

math.CO2025

Proper conflict-free degree-choosability of outerplanar graphs

Masaki Kashima, Riste Škrekovski, Rongxing Xu

math.CO2025

Results on proper conflict-free list coloring of graphs

Masaki Kashima, Riste Škrekovski, Rongxing Xu

Given a graph $G$ and a mapping $f : V (G) \to N$ , an $f$ -list assignment of $G$ is a function that maps each $v \in V (G)$ to a set of at least $f (v)$ colors. For an $f$ -list…

math.CO2023

On Two problems of defective choosability

Jie Ma, Rongxing Xu, Xuding Zhu

Given positive integers $p \geq k$ , and a non-negative integer $d$ , we say a graph $G$ is $(k, d, p)$ -choosable if for every list assignment $L$ with $∣ L (v) ∣ \geq k$ for each $v \in V(…

math.CO2022

Decomposition of triangle-free planar graphs

Rongxing Xu, Xuding Zhu

A decomposition of a graph $G$ is a family of subgraphs of $G$ whose edge sets form a partition of $E (G)$ . In this paper, we prove that every triangle-free planar graph $G$ can be…

math.CO2021

Extended Double Covers and Homomorphism Bounds of Signed Graphs

Florent Foucaud, Reza Naserasr, Rongxing Xu

A \emph{signed graph} $(G, σ)$ is a graph $G$ together with an assignment $σ : E (G) \to {+, -}$ . The notion of homomorphisms of signed graphs is a relatively new development…

math.CO2021★ 2 cited

The strong fractional choice number and the strong fractional paint number of graphs

Rongxing Xu, Xuding Zhu

This paper studies the strong fractional choice number $c h_{f}^{s} (G)$ and the strong fractional paint number $χ_{f, P}^{s} (G)$ of a graph $G$ . We prove that these parameters of any finit…

math.CO2021★ 3 cited

Mapping sparse signed graphs to $(K_{2 k}, M)$

Reza Naserasr, Riste Škrekovski, Zhouningxin Wang +1

A homomorphism of a signed graph $(G, σ)$ to $(H, π)$ is a mapping of vertices and edges of $G$ to (respectively) vertices and edges of $H$ such that adjacencies, incidences and th…

math.CO2020

The strong fractional choice number of $3$ -choice critical graphs

Rongxing Xu, Xuding Zhu

A graph $G$ is called $3$ -choice critical if $G$ is not $2$ -choosable but any proper subgraph is $2$ -choosable. A graph $G$ is strongly fractional $r$ -choosable if $G$ is $(a, b)$ -c…

math.CO2020

Multiple list colouring of $3$ -choice critical graphs

Rongxing Xu, Xuding Zhu

A graph $G$ is called $3$ -choice critical if $G$ is not $2$ -choosable but any proper subgraph is $2$ -choosable. A characterization of $3$ -choice critical graphs was given by Voigt…

math.CO2017

List colouring of graphs and generalized Dyck paths

Rongxing Xu, Yeong-Nan Yeh, Xuding Zhu

The Catalan numbers occur in various counting problems in combinatorics. This paper reveals a connection between the Catalan numbers and list colouring of graphs. Assume $G$ is a g…

On the minimum number of triangles in balanced tripartite graphs with large minimum degree

On the maximum number of triangles in tripartite graphs with no 4-cycles between any two parts

Codegree Thresholds for λ-Choosability of Graphs

The strong fractional choice number of triangle-free planar graphs

Degree-choosability of proper conflict-free list coloring of sparse graphs

Partitioning triangle-free planar graphs into a forest and a linear forest

Remarks on proper conflict-free degree-choosability of graphs with prescribed degeneracy

Proof of a conjecture of Voss on bridges of longest cycles

Proper conflict-free degree-choosability of outerplanar graphs

Results on proper conflict-free list coloring of graphs

On Two problems of defective choosability

Decomposition of triangle-free planar graphs

Extended Double Covers and Homomorphism Bounds of Signed Graphs

The strong fractional choice number and the strong fractional paint number of graphs

Mapping sparse signed graphs to (K2k​,M)

The strong fractional choice number of 3-choice critical graphs

Multiple list colouring of 3-choice critical graphs

List colouring of graphs and generalized Dyck paths

On the maximum number of triangles in tripartite graphs with no $4$ -cycles between any two parts

Codegree Thresholds for $λ$ -Choosability of Graphs

Mapping sparse signed graphs to $(K_{2 k}, M)$

The strong fractional choice number of $3$ -choice critical graphs

Multiple list colouring of $3$ -choice critical graphs