Results 21 to 30 of about 132 (84)

Disproof of a conjecture on the minimum Wiener index of signed trees

, 2022
The Wiener index of a connected graph is the sum of distances between all unordered pairs of vertices. Sam Spiro [The Wiener index of signed graphs, Appl. Math.
Guo, Songlin, Wang, Chuanming, Wang, Wei
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Bounds for the Gutman-Milovanovic index and some applications [PDF]

In this paper, we examine the Gutman-Milovanovic index and establish new upper and lower bounds for it. These bounds include terms related to the general sum connectivity index, the general second Zagreb index, and the hyperbolicity constant of the ...
Granados, Ana, Portilla, Ana, Quintana Mato, Yamilet del Carmen, Tourís, Eva   +3 more
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Mathematical and chemistry properties of geometry-based invariants

, 2022
Recently, based on elementary geometry, Gutman proposed several geometry-based invariants (i.e., $SO$, $SO_{1}$, $SO_{2}$, $SO_{3}$, $SO_{4}$, $SO_{5}$, $SO_{6}$). The Sombor index was defined as $SO(G)=\sum\limits_{uv\in E(G)}\sqrt{d_{u}^{2}+d_{v}^{2}}$,
Liu, Hechao
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Predictive modeling of physical properties in silane compounds using topological descriptors: A computational approach

Main Group Metal Chemistry
Silane compounds are a class of chemical compounds composed of silicon (Si) and hydrogen (H), characterized by the general formula SiH4−xRx{{\rm{SiH}}}_{4-x}{R}_{x}, where RR represents various organic groups. The simplest member of this family is silane
Zhang Xiujun, Yousaf Shamaila, Shahzadi Komal, Ibrahim Sobhy M., Aslam Adnan   +4 more
doaj   +1 more source

On the Clean Graph of a Ring

, 2023
Let R be a ring (not necessarily commutative ring) with identity. The clean graph Cl(R) of a ring R is a graph with vertices in the form of ordered pair (e; u), where e is an idempotent of the ring R and u is a unit of the ring R.
Patekar, S. C., Singh, Randhir
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Extremal polygonal chains with respect to the Kirchhoff index

, 2023
The Kirchhoff index is defined as the sum of resistance distances between all pairs of vertices in a graph. This index is a critical parameter for measuring graph structures.
Ma, Qi
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Quasi-Laplacian energy of fractal graphs [PDF]

Graph energy is a measurement of determining the structural information content of graphs. The first Zagreb index can be handled with its connection to graph energy.
BERBERLER, MURAT ERSEN
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Some new bounds on resolvent energy of a graph

Open Mathematics
Let GG be a simple graph of order nn with eigenvalues λ1≥λ2≥…≥λn.{\lambda }_{1}\ge {\lambda }_{2}\ge \ldots \ge {\lambda }_{n}. The resolvent energy of GG is a spectrum-based graph invariant defined as ER(G)=∑i=1n(n−λi)−1.{\rm{ER}}(G)={\sum }_{i=1}^{n ...
Altındağ İlkay, Bozkurt Altındağ Şerife Burcu   +1 more
doaj   +1 more source

The minimum matching energy of unicyclic graphs with fixed number of vertices of degree two

Open Mathematics
The number of jj-matchings in a graph HH is denote by m(H,j)m\left(H,j). If for two graphs H1{H}_{1} and H2{H}_{2}, m(H1,j)≥m(H2,j)m\left({H}_{1},j)\ge m\left({H}_{2},j) for all jj, then we write H1≽H2{H}_{1}\succcurlyeq {H}_{2}.
Bai Yongqiang, Ma Hongping, Zhang Xia
doaj   +1 more source

Estrada index of hypergraphs via eigenvalues of tensors

, 2021
A uniform hypergraph $\mathcal{H}$ is corresponding to an adjacency tensor $\mathcal{A}_\mathcal{H}$. We define an Estrada index of $\mathcal{H}$ by using all the eigenvalues $\lambda_1,\dots,\lambda_k$ of $\mathcal{A}_\mathcal{H}$ as $\sum_{i=1}^k e ...
Bu, Changjiang, Sun, Lizhu, Zhou, Hong
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