Results 21 to 30 of about 1,442 (223)
On the index of bicyclic graphs with perfect matchings
Discrete Mathematics, 2004 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
AnAn Chang, Feng Tian, Aimei Yu
openaire +3 more sources
On the Hosoya Indices of Bicyclic Graphs with Small Diameter
Journal of Chemistry, 2021 Let G be a graph. The Hosoya index of G, denoted by zG, is defined as the total number of its matchings. The computation of zG is NP-Complete. Wagner and Gutman pointed out that it is difficult to obtain results of the maximum Hosoya index among tree ...
Tingzeng Wu, Yong Yu
doaj +2 more sources
Degree distance of unicyclic and bicyclic graphs
Discrete Applied Mathematics, 2011 zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Aleksandar Ilic +4 more
openaire +2 more sources
Extremal Bicyclic Graphs with Respect to Permanental Sums and Hosoya Indices
AxiomsGraph polynomials is one of the important research directions in mathematical chemistry. The coefficients of some graph polynomials, such as matching polynomial and permanental polynomial, are related to structural properties of graphs.
Tingzeng Wu, Yinggang Bai, Shoujun Xu
doaj +2 more sources
Hosoya Indices of Bicyclic Graphs
Croatica Chemica Acta, 2009 Given a molecular graph G, the Hosoya index Z(G) of G is defined as the total number of the matchings of the graph. Let Bn denote the set of bicyclic graphs on n vertices. In this paper, the minimal, the second-, the third-, the fourth-, and the fifth-minimal Hosoya indices of bicyclic graphs in the set Bn are characterized.
Li, Shuchao, Li, Xuechao, Zhu, Zhongxun
openaire +3 more sources
Unbalanced unicyclic and bicyclic graphs with extremal spectral radius [PDF]
, 2021 summary:A signed graph $\Gamma $ is a graph whose edges are labeled by signs. If $\Gamma $ has $n$ vertices, its spectral radius is the number $\rho (\Gamma ) := \max \{ | \lambda _i(\Gamma ) | \colon 1 \leq i \leq n \}$, where $\lambda _1(\Gamma ) \geq \
Brunetti, Maurizio +2 more
core +2 more sources
The nullity of bicyclic signed graphs [PDF]
Linear and Multilinear Algebra, 2013 Let Γbe a signed graph and let A(Γ) be the adjacency matrix of Γ. The nullity of Γis the multiplicity of eigenvalue zero in the spectrum of A(Γ). In this paper we characterize the signed graphs of order n with nullity n-2 or n-3, and introduce a graph transformation which preserves the nullity.
Fan, Yi-Zheng +2 more
openaire +2 more sources
Signed bicyclic graphs with minimal index [PDF]
, 2023 The index of a signed graph \Sigma = (G; \sigma) is just the largest eigenvalue of its adjacency matrix. For any n > 4 we identify the signed graphs achieving the minimum index in the class of signed bicyclic graphs with n vertices.
Ciampella A., Brunetti M.
core +1 more source
On the index of unbalanced signed bicyclic graphs [PDF]
Computational and Applied Mathematics, 2021 In this paper, we focus on the index ( largest eigenvalue) of the adjacency matrix of connected signed graphs. We give some general results on the index when the corresponding signed graph is perturbed. As applications, we determine the first five largest index among all unbalanced bicyclic graphs on n >= 36 vertices together with the corresponding ...
Changxiang He +3 more
openaire +2 more sources
Ordering graphs with large eccentricity-based topological indices
Journal of Inequalities and Applications, 2021 For a connected graph, the first Zagreb eccentricity index ξ 1 $\xi _{1}$ is defined as the sum of the squares of the eccentricities of all vertices, and the second Zagreb eccentricity index ξ 2 $\xi _{2}$ is defined as the sum of the products of the ...
Yunfang Tang, Xuli Qi
doaj +1 more source