Results 11 to 20 of about 445 (75)

Two short proofs of the bounded case of S.B. Rao's degree sequence conjecture [PDF]

open access: yes, 2011
S. B. Rao conjectured that graphic sequences are well-quasi-ordered under an inclusion based on induced subgraphs. This conjecture has now been settled completely by M. Chudnovsky and P. Seymour.
Altomare   +4 more
core   +1 more source

Bicircular signed-graphic matroids [PDF]

open access: yes, 2013
Several matroids can be defined on the edge set of a graph. Although historically the cycle matroid has been the most studied, in recent times, the bicircular matroid has cropped up in several places.
Sivaraman, Vaidy
core   +1 more source

The Minimum Harmonic Index for Unicyclic Graphs with Given Diameter

open access: yesDiscussiones Mathematicae Graph Theory, 2018
The harmonic index of a graph G is defined as the sum of the weights 2d(u)+d(v)${2 \over {d(u) + d(v)}}$ of all edges uv of G, where d(u) denotes the degree of a vertex u in G.
Zhong Lingping
doaj   +1 more source

Computational Analysis of new Degree-based descriptors of oxide networks

open access: yesOpen Chemistry, 2019
Oxide networks have diverse applications in the polymer and pharmaceutical industries. Polynomials and degree-based topological indices have tendencies to correlate properties of molecular graphs.
Hussain Zafar   +5 more
doaj   +1 more source

More on Comparison Between First Geometric-Arithmetic Index and Atom-Bond Connectivity Index [PDF]

open access: yes, 2015
The first geometric-arithmetic (GA) index and atom-bond connectivity (ABC) index are molecular structure descriptors which play a significant role in quantitative structure-property relationship (QSPR) and quantitative structure-activity relationship ...
Akbar Ali   +3 more
core   +2 more sources

The Second Neighbourhood for Bipartite Tournaments

open access: yesDiscussiones Mathematicae Graph Theory, 2019
Let T (X ∪ Y, A) be a bipartite tournament with partite sets X, Y and arc set A. For any vertex x ∈ X ∪Y, the second out-neighbourhood N++(x) of x is the set of all vertices with distance 2 from x.
Li Ruijuan, Sheng Bin
doaj   +1 more source

On Implicit Heavy Subgraphs and Hamiltonicity of 2-Connected Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A graph G of order n is implicit claw-heavy if in every induced copy of K1,3 in G there are two non-adjacent vertices with sum of their implicit degrees at least n. We study various implicit degree conditions (including, but not limiting to, Ore- and Fan-
Zheng Wei, Wideł Wojciech, Wang Ligong
doaj   +1 more source

A Study on Set-Graphs [PDF]

open access: yes, 2015
A \textit{primitive hole} of a graph $G$ is a cycle of length $3$ in $G$. The number of primitive holes in a given graph $G$ is called the primitive hole number of that graph $G$. The primitive degree of a vertex $v$ of a given graph $G$ is the number of
C. Susanth   +4 more
core   +1 more source

The H-force sets of the graphs satisfying the condition of Ore’s theorem

open access: yesOpen Mathematics, 2020
Let G be a Hamiltonian graph. A nonempty vertex set X⊆V(G)X\subseteq V(G) is called a Hamiltonian cycle enforcing set (in short, an H-force set) of G if every X-cycle of G (i.e., a cycle of G containing all vertices of X) is a Hamiltonian cycle.
Zhang Xinhong, Li Ruijuan
doaj   +1 more source

On Order Prime Divisor Graphs of Finite Groups

open access: yesDiscussiones Mathematicae - General Algebra and Applications, 2021
The order prime divisor graph 𝒫𝒟(G) of a finite group G is a simple graph whose vertex set is G and two vertices a, b ∈ G are adjacent if and only if either ab = e or o(ab) is some prime number, where e is the identity element of the group G and o(x ...
Sen Mridul K.   +2 more
doaj   +1 more source

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