Results 11 to 20 of about 56 (44)
On Singular Signed Graphs with Nullspace Spanned by a Full Vector: Signed Nut Graphs
Discussiones Mathematicae Graph Theory, 2022 A signed graph has edge weights drawn from the set {+1, −1}, and is sign-balanced if it is equivalent to an unsigned graph under the operation of sign switching; otherwise it is sign-unbalanced.
Bašić Nino +3 more
doaj +1 more source
On the first Zagreb index of graphs with Self-Loops
AKCE International Journal of Graphs and Combinatorics, 2023 Some of the most comprehensively studied degree-based topological indices are the Zagreb indices. The first Zagreb index [Formula: see text] of a graph G is defined as the sum of squares of the degrees of the vertices.
Shashwath S. Shetty, Arathi Bhat K
doaj +1 more source
Some topological indices of dendrimers determined by their Banhatti polynomials
Heterocyclic Communications, 2020 Several properties of chemical compounds in a molecular structure can be determined with the aid of mathematical languages provided by various types of topological indices.
Chu Zheng-Qing +6 more
doaj +1 more source
Spectral properties of balanced trees and dendrimers
, 2022 We investigate the spectral properties of balanced trees and dendrimers, with a view toward unifying and improving the existing results. Here we find a semi-factorized formula for their characteristic polynomials.
Damnjanović, Ivan +2 more
core +1 more source
, 2023 The network systems and graphical analysis through the study ofstructural characteristics is a vast field of growing importance inresearch. Topological indices have a significant and crucial role inthe study of structure–property relationships.
Ishita Sarkar +2 more
core +2 more sources
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 +3 more
core +2 more sources
New bounds for variable topological indices and applications [PDF]
One of the most important information related to molecular graphs is given by the determination (when possible) of upper and lower bounds for their corresponding topological indices. Such bounds allow to establish the approximate range of the topological
Granados, Ana +3 more
core +1 more source
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
core
An algorithmic approach to extending a theorem on extremal trees by Wang
, 2023 Let $\mathcal{T}_D$ be the set containing all the trees corresponding to a given degree sequence $D$ and let $R_\mathcal{F}$ be the graph invariant defined via \[ R_\mathcal{F} = \sum_{u \sim v} \mathcal{F}(\mathrm{deg}(u), \mathrm{deg}(v)) , \] where ...
Damnjanović, Ivan, Ranđelović, Žarko
core
The minimum matching energy of unicyclic graphs with fixed number of vertices of degree two
Open MathematicsThe 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