Results 51 to 60 of about 445 (76)

New Formulae for the Decycling Number of Graphs

Discussiones Mathematicae Graph Theory, 2019
A set S of vertices of a graph G is called a decycling set if G−S is acyclic. The minimum order of a decycling set is called the decycling number of G, and denoted by ∇(G). Our results include: (a) For any graph G,, where T is taken over all the spanning
Yang Chao, Ren Han
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The Subset-Strong Product of Graphs

Annales Mathematicae Silesianae
In this paper, we introduce the subset-strong product of graphs and give a method for calculating the adjacency spectrum of this product. In addition, exact expressions for the first and second Zagreb indices of the subset-strong products of two graphs ...
Eliasi Mehdi
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Several Zagreb indices of power graphs of finite non-abelian groups. [PDF]

Heliyon, 2023
Ismail R, Ali F, Qasim R, Naeem M, Mashwani WK, Khan S.   +5 more
europepmc   +1 more source

On the maximum atom-bond sum-connectivity index of graphs

Open Mathematics
The atom-bond sum-connectivity (ABS) index of a graph GG with edges e1,…,em{e}_{1},\ldots ,{e}_{m} is the sum of the numbers 1−2(dei+2)−1\sqrt{1-2{\left({d}_{{e}_{i}}+2)}^{-1}} over 1≤i≤m1\le i\le m, where dei{d}_{{e}_{i}} is the number of edges adjacent
Alraqad Tariq, Saber Hicham, Ali Akbar, Albalahi Abeer M.   +3 more
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On the first Zagreb index and multiplicative Zagreb coindices of graphs

Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2016
For a (molecular) graph G with vertex set V (G) and edge set E(G), the first Zagreb index of G is defined as , where dG(vi) is the degree of vertex vi in G. Recently Xu et al. introduced two graphical invariants and named as first multiplicative Zagreb
Das Kinkar Ch., Akgunes Nihat, Togan Muge, Yurttas Aysun, Cangul I. Naci, Cevik A. Sinan   +5 more
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An extremal problem on potentially K p,1,1-graphic sequences

Discrete Mathematics & Theoretical Computer Science, 2005
A sequence S is potentially K p,1,1 graphical if it has a realization containing a K p,1,1 as a subgraph, where K p,1,1 is a complete 3-partite graph with partition sizes p,1,1.
Chunhui Lai
doaj  

A novel algebraic technique for adjacency matrices of some derived graphs

Mathematical and Computer Modelling of Dynamical Systems
Graph energy has been the main concern of spectral graph theory in the last five decades. The classical graph energy is the sum of the absolute values of the eigenvalues of the adjacency matrix. In many research papers, different versions of graph energy
Hacer Ozden Ayna, Aysun Yurttas Gunes, Sadik Delen, Medha Itagi Huilgol, Berke Ozmen, Ismail Naci Cangul   +5 more
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On the maximum atom-bond sum-connectivity index of molecular trees

AKCE International Journal of Graphs and Combinatorics
Let G be a graph with V(G) and E(G), as vertex set and edge set, respectively. The atom-bond sum-connectivity (ABS) index is a vertex-based topological index which is defined as [Formula: see text] where [Formula: see text] is the degree of the vertex a.
Zhonglin Cheng, Akbar Jahanbani, Jun Wang   +2 more
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On the vv-degree based first Zagreb index of graphs

AKCE International Journal of Graphs and Combinatorics
A topological index is a graph invariant applicable in chemistry. The first Zagreb index is a topological index based on the vertex degrees of molecular graphs. For any graph G, the first Zagreb index [Formula: see text] is equal to the sum of squares of
L. Anusha, N. V. Sayinath Udupa, N. Prathviraj   +2 more
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Network-based kinetic models: Emergence of a statistical description of the graph topology

European Journal of Applied Mathematics
In this paper, we propose a novel approach that employs kinetic equations to describe the collective dynamics emerging from graph-mediated pairwise interactions in multi-agent systems.
Marco Nurisso, Matteo Raviola, Andrea Tosin   +2 more
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