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pro vyhledávání: '"Huang, Qiongxiang"'
Let $G_{n,\gamma}$ be the set of all connected graphs on $n$ vertices with domination number $\gamma$. A graph is called a minimizer graph if it attains the minimum spectral radius among $G_{n,\gamma}$. Very recently, Liu, Li and Xie [Linear Algebra
Externí odkaz:
http://arxiv.org/abs/2307.15605
Autor:
Li, Deqiong, Huang, Qiongxiang
It is well known that a graph $G$ has a symmetric spectrum if and only if it is bipar?tite, a signed graph $\Gamma=(G,\sigma)$ has a symmetric spectrum if $G$ is bipartite. However, there exists a spectrally symmetric signed graph $\Gamma=(G,\sigma)$
Externí odkaz:
http://arxiv.org/abs/2304.06864
The signless Laplacian matrix in graph spectra theory is a remarkable matrix of graphs, and it is extensively studied by researchers. In 1981, Cvetkovi\'{c} pointed $12$ directions in further investigations of graph spectra, one of which is "classify
Externí odkaz:
http://arxiv.org/abs/2209.01771
Autor:
Song, Rui, Huang, Qiongxiang
A topological index reflects the physical, chemical and structural properties of a molecule, and its study has an important role in molecular topology, chemical graph theory and mathematical chemistry. It is a natural problem to characterize non-isom
Externí odkaz:
http://arxiv.org/abs/2207.03357
Let $\mathbb{G}_{n,\alpha}$ be the set of connected graphs with order $n$ and independence number $\alpha$. Given $k=n-\alpha$, the graph with minimum spectral radius among $\mathbb{G}_{n,\alpha}$ is called the minimizer graph. Stevanovi\'{c} in the
Externí odkaz:
http://arxiv.org/abs/2206.09152
A graph is minimally $k$-connected ($k$-edge-connected) if it is $k$-connected ($k$-edge-connected) and deleting arbitrary chosen edge always leaves a graph which is not $k$-connected ($k$-edge-connected). A classic result of minimally $k$-connected
Externí odkaz:
http://arxiv.org/abs/2206.07872
Autor:
Hu, Yarong, Huang, Qiongxiang
In this paper, we introduce the notion of the quadratic graph, that is a graph whose eigenvalues are integral or quadratic algebraic integral, and determine nine infinite families of quadratic starlike trees, which are just all the quadratic starlike
Externí odkaz:
http://arxiv.org/abs/2103.15403
Autor:
Wang, Peng, Huang, Qiongxiang
For a simple graph $G$ with $n$ vertices, $m$ edges and signless Laplacian eigenvalues $q_{1} \geq q_{2} \geq \cdots \geq q_{n} \geq 0$, its the signless Laplacian energy $QE(G)$ is defined as $QE(G) = \sum_{i=1}^{n}|q_{i} - \bar{d} |$, where $\bar{d
Externí odkaz:
http://arxiv.org/abs/2010.03980
Recently, D. Vuki$\check{c}$evi$\acute{c}$ and J. Sedlar in \cite{Vuki} introduced an order "$\preceq$" on $\mathcal{T}_n$, the set of trees on $n$ vertices, such that the topological index $F$ of a graph is a function defined on the order set $\lang
Externí odkaz:
http://arxiv.org/abs/2010.03981
Publikováno v:
Graphs and Combinatorics 38 (2022), 161, 22 pages
The quadratic embedding constant (QE constant) of a graph is a new characteristic value of a graph defined through the distance matrix. We derive formulae for the QE constants of the join of two regular graphs, double graphs and certain lexicographic
Externí odkaz:
http://arxiv.org/abs/2001.06752