Results 11 to 20 of about 445 (76)

Upward-closed hereditary families in the dominance order [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2022
The majorization relation orders the degree sequences of simple graphs into posets called dominance orders. As shown by Ruch and Gutman (1979) and Merris (2002), the degree sequences of threshold and split graphs form upward-closed sets within the ...
Michael D. Barrus, Jean A. Guillaume
doaj   +1 more source

Conflict-Free Vertex Connection Number At Most 3 and Size of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A path in a vertex-coloured graph is called conflict-free if there is a colour used on exactly one of its vertices. A vertex-coloured graph is said to be conflict-free vertex-connected if any two distinct vertices of the graph are connected by a conflict-
Doan Trung Duy, Schiermeyer Ingo
doaj   +1 more source

Spectra of Orders for k-Regular Graphs of Girth g

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A (k, g)-graph is a k-regular graph of girth g. Given k ≥ 2 and g ≥ 3, infinitely many (k, g)-graphs of infinitely many orders are known to exist. Our goal, for given k and g, is the classification of all orders n for which a (k, g)-graph of order n ...
Jajcay Robert, Raiman Tom
doaj   +1 more source

An extremal problem on potentially K_p,1,1-graphic sequences [PDF]

open access: yesDiscrete 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   +1 more source

Banhatti, revan and hyper-indices of silicon carbide Si2C3-III[n,m]

open access: yesOpen Chemistry, 2021
In recent years, several structure-based properties of the molecular graphs are understood through the chemical graph theory. The molecular graph GG of a molecule consists of vertices and edges, where vertices represent the atoms in a molecule and edges ...
Zhao Dongming   +6 more
doaj   +1 more source

On Factorable Bigraphic Pairs

open access: yesDiscussiones Mathematicae Graph Theory, 2020
Let S = (a1,. . . , am; b1, . . . , bn), where a1, . . . , am and b1, . . . , bn are two sequences of nonnegative integers. We say that S is a bigraphic pair if there exists a simple bipartite graph G with partite sets {x1, x2, . . . , xm} and {y1, y2, .
Yin Jian-Hua, Li Sha-Sha
doaj   +1 more source

Solutions to problems about potentially Ks,t-bigraphic pair

open access: yesOpen Mathematics, 2022
Let S=(a1,…,am;b1,…,bn)S=\left({a}_{1},\ldots ,{a}_{m};\hspace{0.33em}{b}_{1},\ldots ,{b}_{n}), where a1,…,am{a}_{1},\ldots ,{a}_{m} and b1,…,bn{b}_{1},\ldots ,{b}_{n} are two nonincreasing sequences of nonnegative integers. The pair S=(a1,…,am;b1,…,bn)S=
Yin Jian-Hua, Zhang Liang
doaj   +1 more source

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

Proper Rainbow Connection Number of Graphs

open access: yesDiscussiones Mathematicae Graph Theory, 2021
A path in an edge-coloured graph is called a rainbow path if its edges receive pairwise distinct colours. An edge-coloured graph is said to be rainbow connected if any two distinct vertices of the graph are connected by a rainbow path.
Doan Trung Duy, Schiermeyer Ingo
doaj   +1 more source

Hosoya properties of the commuting graph associated with the group of symmetries

open access: yesMain Group Metal Chemistry, 2021
A vast amount of information about distance based graph invariants is contained in the Hosoya polynomial. Such an information is helpful to determine well-known distance based molecular descriptors.
Abbas Ghulam   +4 more
doaj   +1 more source

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