Results 71 to 80 of about 1,099 (89)

A Note on Upper Bounds for Some Generalized Folkman Numbers

Discussiones Mathematicae Graph Theory, 2019
We present some new constructive upper bounds based on product graphs for generalized vertex Folkman numbers. They lead to new upper bounds for some special cases of generalized edge Folkman numbers, including the cases Fe(K3, K4 − e; K5) ≤ 27 and Fe(K4 −
Xu Xiaodong, Liang Meilian, Radziszowski Stanisław   +2 more
doaj   +1 more source

Some results involving the Aα-eigenvalues for graphs and line graphs

Special Matrices
Let GG be a simple graph with adjacency matrix A(G)A\left(G), degree diagonal matrix D(G),D\left(G), and let l(G)l\left(G) be the line graph of GG. In 2017, Nikiforov defined the Aα{A}_{\alpha }-matrix of GG, Aα(G){A}_{\alpha }\left(G), as a linear ...
da Silva Júnior João Domingos G., Oliveira Carla Silva, da Costa Liliana Manuela G. C.   +2 more
doaj   +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
doaj   +1 more source

On the δ-chromatic numbers of the Cartesian products of graphs

Open Mathematics
In this work, we study the δ\delta -chromatic number of a graph, which is the chromatic number of the δ\delta -complement of a graph. We give a structure of the δ\delta -complements and sharp bounds on the δ\delta -chromatic numbers of the Cartesian ...
Tangjai Wipawee, Pho-on Witsarut, Vichitkunakorn Panupong   +2 more
doaj   +1 more source

On concentrators and related approximation constants [PDF]

, 2013
Bondarenko, A., Prymak, A., Radchenko, D.   +2 more
core   +2 more sources

Functions on adjacent vertex degrees of trees with given degree sequence

Open Mathematics, 2014
Wang Hua
doaj   +1 more source

Extremal values on Zagreb indices of trees with given distance k-domination number. [PDF]

J Inequal Appl, 2018
Pei L, Pan X.
europepmc   +1 more source

On Properties of Distance-Based Entropies on Fullerene Graphs. [PDF]

Entropy (Basel), 2019
Ghorbani M, Dehmer M, Rajabi-Parsa M, Mowshowitz A, Emmert-Streib F.   +4 more
europepmc   +1 more source

Some new sharp bounds for the spectral radius of a nonnegative matrix and its application. [PDF]

J Inequal Appl, 2017
He J, Liu YM, Tian JK, Liu XH.
europepmc   +1 more source

The F-coindex of some graph operations. [PDF]

Springerplus, 2016
De N, Nayeem SM, Pal A.
europepmc   +1 more source