Graphs with maximal irregularity

WebApr 20, 2024 · The irregularity of a graph G = (V, E) is defined as the sum of imbalances ∣du − dv∣ over all edges uv ∈ E, where du denotes the degree of the vertex u in G. This graph invariant, introduced by Albertson in 1997, is a measure of the defect of regularity of a graph. In this paper, we completely determine the extremal values of the irregularity of … WebMar 16, 2024 · The mentioned authors determined all graphs with maximal total irregularity. They also shown that the star graph has the maximum total irregularity in the class of all n -vertex trees. Abdo and Dimitrov [ 1 ], obtained upper bounds for the total irregularity of some graph operations in terms of the total irregularity of their factors.

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WebSep 1, 2024 · Here, we characterize general graphs with maximal σ irregularity. We also present lower bounds on the maximal σ irregularity of graphs with fixed minimal and/or … WebDec 28, 2024 · Abstract. A modular irregular graph is a graph that admits a modular irregular labeling. A modular irregular labeling of a graph of order is a mapping of the set of edges of the graph to such that the weights of all vertices are different. The vertex weight is the sum of its incident edge labels, and all vertex weights are calculated with the sum … how to store a banana https://janradtke.com

Modular Irregular Labeling on Double-Star and Friendship Graphs - Hindawi

Web3. Lower Bounds on Graphs with Maximal Irregularity. The authors consider graphs with maximal irregularity and prescribed minimal or/and maximal degrees. First, the authors show a lower bound for graphs with … WebMar 1, 2024 · Recently, Gutman introduced the class of stepwise irregular graphs and studied their properties. A graph is stepwise irregular if the difference between the degrees of any two adjacent vertices is exactly one. In this paper, we get some upper bounds on the maximum degree and sharp upper bounds on the size of stepwise irregular graphs. Web3. Lower Bounds on Graphs with Maximal Irregularity. The authors consider graphs with maximal irregularity and prescribed minimal or/and maximal degrees. First, the authors show a lower bound for graphs with … read the heart of philadelphia

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Graphs with maximal irregularity

Graphs with maximum irregularity - Springer

WebAlizadeh et al. (2024) studied the irregularity of π-permutation graphs, Fibonacci cubes, and trees. Hansen and Mélot (2005) characterized the graphs of order n and size m that … WebIrregularity indices are usually used for quantitative characterization of the topological structures of non-regular graphs. In numerous problems and applications, especially in the fields of chemistry and material engineering, it is useful to be aware of the irregularity of a molecular structure. Furthermore, the evaluation of the irregularity of graphs is valuable …

Graphs with maximal irregularity

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WebDec 1, 2024 · The extremal irregularity of connected graphs with given number of pendant vertices. The irregularity of a graph G = (V, E) is defined as the sum of imbalances ∣du … WebMar 15, 2024 · Abdo et al. [2] determined all graphs with maximal total irregularity and proved that among all trees of the same order the star has the maximum total irregularity. You et al. [7], investigated the total irregularity of bicyclic graphs and characterized the graph with the maximal total irregularity among all bicyclic graphs on n vertices.

Webvertex of degree n - 1. If irr(e ) = n - 2 would hold for all edges of a graph, then this graph would have maximal irregularity. In the case of trees, this condition is obeyed by the star (and only by it). Thus we arrive at the following simple result: Lemma 1.2. Among trees of ordern, the star Sn is the unique tree with greatest irregularity ... WebJul 28, 2024 · An inclusive distance vertex irregular labeling of a graph G is an assignment of positive integers \(\{1, 2, \ldots , k\}\) to the vertices of G such that for every vertex the sum of numbers assigned to its closed neighborhood is different. The minimum number k for which exists an inclusive distance vertex irregular labeling of G is denoted by …

WebNov 25, 2024 · Abstract. We prove a sharp upper bound on the number of shortest cycles contained inside any connected graph in terms of its number of vertices, girth, and maximal degree. Equality holds only for Moore graphs, which gives a new characterization of these graphs. In the case of regular graphs, our result improves an inequality of Teo and Koh. WebFeb 19, 1999 · The graphs with maximal total irregularity are determined. It is also shown that among all trees of same order the star graph has the maximal total irregularity. View.

WebAs a standard notation, assume that G = G(V,E) is a finite, simple and undirected graph with p vertices and q edges. A labeling of a graph is any mapping that sends some set of graph elements to a set of numbers (usually positive integers). If the domain is the vertex-set or the edge-set, the labelings are called respectively vertex-labelings or edge-labelings. If the …

WebJan 30, 2024 · The maximum degree of a graph G is denoted by Δ (G). Lemma 2. Let k and n be fixed integers satisfying 0 ≤ k ≤ n − 2. If G is a graph possessing the greatest sigma index over the family of all connected k-cyclic graphs of order n, then Δ (G) = n − 1. Proof. Contrarily, assume that v ∈ V (G) such that d v = Δ (G) ≤ n − 2. read the heir online freeWebDec 11, 2024 · General graphs with maximal σ irregularity. In order to characterize graphs with maximal σ irregularity, we first determine the minimum number of … read the heroine of drayfoxWebSep 15, 2024 · It seems that the oldest numerical measure of graph irregularity was proposed by Collatz and Sinogowitz [20] who defined it as C S ( G) = λ 1 − 2 m n where λ1 is the largest eigenvalue of the adjacency matrix, usually referred to as the spectral radius of the underlying graph [21], [38]. how to store a cake with fondantWebHere, we characterise the nonregular graphs with minimal total irregularity and thereby resolve the recent conjecture by Zhu et al. [‘The minimal total irregularity of graphs’, Preprint, 2014, arXiv:1404.0931v1] about the lower bound on the minimal total read the hero who laughsWebMar 15, 2024 · Abdo et al. [2] determined all graphs with maximal total irregularity and proved that among all trees of the same order the star has the maximum total … read the hero returns light novelWebWe also present lower bounds on the maximal irregularity of graphs with fixed minimal and/or maximal vertex degrees, and consider an approximate computation of the … read the hero returns novelWebA graph is thus locally irregular if for each vertex v of G the neighbors of v have distinct degrees, and these graphs are thus termed highly irregular graphs. Properties of … read the herb king