Yen-Jen Cheng

activity

20152025

most citedThe Boolean Rainbow Ramsey Number of Antichains, Boolean Posets, and Chains

3 citations · 4 across the 12 of their papers we have counts for

collaborators

12 papers

math.CO2025

Nordhaus-Gaddum inequality for the spectral radius of a graph of order $n$

Yen-Jen Cheng, Chih-wen Weng

We determine the extremal graph $G$ of order $n$ that maximizes the sum of the spectral radii of $G$ and its complement. This resolves a conjecture posed by Stevanović in 2007.

math.CO2023

A matrix realization of spectral bounds

Yen-Jen Cheng, Chih-wen Weng

We give a unified and systematic way to find bounds for the largest real eigenvalue of a nonnegative matrix by considering its modified quotient matrix. We leverage this insight to…

math.CO2022

Statistics of Partial Permutations via Catalan matrices

Yen-Jen Cheng, Sen-Peng Eu, Hsiang-Chun Hsu

A generalized Catalan matrix $(a_{n, k})_{n, k \geq 0}$ is generated by two seed sequences $s = (s_{0}, s_{1}, \dots)$ and $t = (t_{1}, t_{2}, \dots)$ together with a recurrence re…

math.CO2022

On Signed Multiplicities of Schur Expansions Surrounding Petrie Symmetric Functions

Yen-Jen Cheng, Meng-Chien Chou, Sen-Peng Eu +2

For $k \geq 1$ , the homogeneous symmetric functions $G (k, m)$ of degree $m$ defined by $\sum_{m \geq 0} G (k, m) z^{m} = \prod_{i \geq 1} (1 + x_{i} z + x_{i}^{2} z^{2} + \dots + x_{i}^{k - 1} z^{k - 1})$ are…

math.CO2021

Sharp bounds of the $A_{α}$ -spectral radii of mixed trees

Yen-Jen Cheng, Louis Kao, Chih-Wen Weng

A mixed tree is a tree in which both directed arcs and undirected edges may exist. Let $T$ be a mixed tree with $n$ vertices and $m$ arcs, where an undirected edge is counted twice…

math.CO2021

Counterexamples of the Bhattacharya-Friedland-Peled conjecture

Yen-Jen Cheng, Chia-An Liu, Chih-wen Weng

The Brauldi-Hoffman conjecture, proved by Rowlinson in 1988, characterized the graph with maximal spectral radius among all simple graphs with prescribed number of edges. In 2008,…

math.CO2021★ 1 cited

Ramsey Properties for $V$ -shaped Posets in the Boolean Lattices

Hong-Bin Chen, Wei-Han Chen, Yen-Jen Cheng +2

Given posets $P_{1}, P_{2}, \dots, P_{k}$ , let the {\em Boolean Ramsey number} $R (P_{1}, P_{2}, \dots, P_{k})$ be the minimum number $n$ such…

math.CO2019★ 3 cited

The Boolean Rainbow Ramsey Number of Antichains, Boolean Posets, and Chains

Hong-Bin Chen, Yen-Jen Cheng, Wei-Tian Li +1

Motivated by the paper of Axenovich and Walzer [2], we study the Ramsey-type problems on the Boolean lattices. Given posets $P$ and $Q$ , we look for the smallest Boolean lattice $\…

math.CO2019

On the integer {k}-domination number of circulant graphs

Yen-Jen Cheng, Hung-Lin Fu, Chia-an Liu

Let $G = (V, E)$ be a simple undirected graph. $G$ is a circulant graph defined on $V = Z_{n}$ with difference set $D \subseteq {1, 2, \dots, ⌊ \frac{n}{2} ⌋}$ provided…

math.CO2018

On the distance matrices of the CP graphs

Yen-Jen Cheng, Jephian C. -H. Lin

This paper introduces a new class of graphs, the CP graphs, and shows that their distance determinant and distance inertia are independent of their structures. The CP graphs includ…

math.CO2017

A matrix realization of spectral bounds of the spectral radius of a nonnegative matrix

Yen-Jen Cheng, Chih-wen Weng

We realize many sharp spectral bounds of the spectral radius of a nonnegative square matrix $C$ by using the largest real eigenvalues of suitable matrices of smaller sizes related…

math.CO2015

An extending result on spectral radius of bipartite graphs

Yen-Jen Cheng, Feng-lei Fan, Chih-wen Weng

Let $G$ denote a bipartite graph with $e$ edges without isolated vertices. It was known that the spectral radius of $G$ is at most the square root of $e$ , and the upper bound is at…

Nordhaus-Gaddum inequality for the spectral radius of a graph of order n

A matrix realization of spectral bounds

Statistics of Partial Permutations via Catalan matrices

On Signed Multiplicities of Schur Expansions Surrounding Petrie Symmetric Functions

Sharp bounds of the Aα​-spectral radii of mixed trees

Counterexamples of the Bhattacharya-Friedland-Peled conjecture

Ramsey Properties for V-shaped Posets in the Boolean Lattices

The Boolean Rainbow Ramsey Number of Antichains, Boolean Posets, and Chains

On the integer {k}-domination number of circulant graphs

On the distance matrices of the CP graphs

A matrix realization of spectral bounds of the spectral radius of a nonnegative matrix

An extending result on spectral radius of bipartite graphs

Nordhaus-Gaddum inequality for the spectral radius of a graph of order $n$

Sharp bounds of the $A_{α}$ -spectral radii of mixed trees

Ramsey Properties for $V$ -shaped Posets in the Boolean Lattices