Results 31 to 40 of about 2,700 (119)
Extremal Graphs for Sombor Index with Given Parameters
Axioms, 2023 In this paper, we present the upper and lower bounds on Sombor index SO(G) among all connected graphs (respectively, connected bipartite graphs). We give some sharp lower and upper bounds on SO(G) among connected graphs in terms of some parameters ...
Wanping Zhang, Jixiang Meng, Na Wang
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Wiener index in graphs given girth, minimum, and maximum degrees
Theory and Applications of Graphs, 2023 Let $G$ be a connected graph of order $n$. The Wiener index $W(G)$ of $G$ is the sum of the distances between all unordered pairs of vertices of $G$.
Fadekemi J. Osaye +3 more
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Scientia Agricola, 2007 Rubber tree cultivation [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell.-Arg.] uses mostly the budding propagation method, however the expected stand uniformity due to the use of vegetative propagation is theoretical, since high variation for yield ...
Átila Bento Beleti Cardinal +2 more
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Discrete Mathematics, 2000 Let \(G\) denote a strongly-connected digraph with \(n\) nodes, girth \(g\), and diameter \(D\). The author shows that if \(G\) has \(t\) nodes of out-degree one, then \(D\leq n-g+ t\). He also shows that if \(r\) denotes the minimum out-degree of \(G\), then \(g\leq \max\{\lceil n/r\rceil, 2r- 2\}\). This last result implies that when \(n\geq 2r^2- 3r+
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On the Superconnectivity in graphs with odd girth g and even girth h
Electronic Notes in Discrete Mathematics, 2009 A maximally connected graph G of minimum degree δ is said to be superconnected (for short super-κ) if all disconnecting sets of cardinality δ are the neighborhood of some vertex of degree δ. Sufficient conditions on the diameter to guarantee that a graph of odd girth g and even girth h ≥ g + 3 is super-κ are stated. Also polarity graphs are shown to be
Luis Pedro Montejano 0001 +2 more
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High-Girth matrices and polarization [PDF]
2015 IEEE International Symposium on Information Theory (ISIT), 2015 The girth of a matrix is the least number of linearly dependent columns, in contrast to the rank which is the largest number of linearly independent columns. This paper considers the construction of {\it high-girth} matrices, whose probabilistic girth is close to its rank.
Emmanuel Abbe, Yuval Wigderson
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Diameter and girth of Torsion Graph
Analele Stiintifice ale Universitatii Ovidius Constanta: Seria Matematica, 2014 Let R be a commutative ring with identity. Let M be an R-module and T (M)* be the set of nonzero torsion elements. The set T(M)* makes up the vertices of the corresponding torsion graph, ΓR(M), with two distinct vertices x, y ∈ T(M)* forming an edge if ...
Rad P. Malakooti +3 more
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Characterization of classes of graphs with large general position number
AKCE International Journal of Graphs and Combinatorics, 2020 Getting inspired by the famous no-three-in-line problem and by the general position subset selection problem from discrete geometry, the same is introduced into graph theory as follows.
Elias John Thomas, Ullas Chandran S. V.
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Journal of Combinatorial Theory, Series B, 1983 Sei \(\Gamma_a\) die Klasse der endlichen zusammenhängenden Graphen vom Minimalgrad mindestens \(a\), und sei \(\Gamma_{a,k}\) die Klasse der \(G \in \Gamma_a\) mit der Taillenweite mindestens \(k\). Satz 1: Für \(q \geq q_n\) ist jedes \(G \in \Gamma_{3,q}\) auf \(K_n\) kontrahierbar. Der Verf. führt den Begriff \(k\)-zyklisch-eckenzusammenhängend ein.
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On the acyclic disconnection and the girth
Discrete Applied Mathematics, 2015 The acyclic disconnection, (omega) over right arrow (D), of a digraph D is the maximum number of connected components of the underlying graph of D - A(D*), where D* is an acyclic subdigraph of D. We prove that (omega) over right arrow (D) >= g - 1 for every strongly connected digraph with girth g >= 4, and we show that (omega) over right arrow (D) = g -
Balbuena Martínez, Maria Camino Teófila +1 more
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