Volume 7 (2024) Issue 2

Author(s): Noha Mohammad Seyam1, Muhammad Faisal Nadeem2
1College of Applied Sciences Mathematical Sciences Department, Umm Al-Qura University, Makkah Saudi Arabia
2Department of Mathematics, COMSATS University Islamabad Lahore Campus, Lahore 54000 Pakistan
Abstract:

An edge irregular \(k\)-labeling of a graph \(G\) is a labeling of vertices of \(G\) with labels from the set \(\{1,2,3,\dots,k\}\) such that no two edges of \(G\) have same weight. The least value of \(k\) for which a graph \(G\) has an edge irregular \(k\)-labeling is called the edge irregularity strength of \(G\). Ahmad et. al. [1] showed the edge irregularity strength of some particular classes of Toeplitz graphs. In this paper we generalize those results and finds the exact values of the edge irregularity strength for some generalize classes of Toeplitz graphs.

Author(s): Zaryab Hussain1, Muhammad Ahsan Binyamin2
1School of Mathematics and Statistics, Northwestern Polytechnical University, Xi’an, Shaanxi 710129, China
2Department of Mathematics, Government College University Faisalabad, Faisalabad 38000, Pakistan
Abstract:

The eccentric atom-bond sum-connectivity \(\left(ABSC_{e}\right)\) index of a graph \(G\) is defined as \(ABSC_{e}(G)=\sum\limits_{uv\in E(G)}\sqrt{\frac{e_{u}+e_{v}-2}{e_{u}+e_{v}}}\), where \(e_{u}\) and \(e_{v}\) represent the eccentricities of \(u\) and \(v\) respectively. This work presents precise upper and lower bounds for the \(ABSC_{e}\) index of graphs based on their order, size, diameter, and radius. Moreover, we find the maximum and minimum \(ABSC_{e}\) index of trees based on the specified matching number and the number of pendent vertices.

Author(s): Rao Li1
1Dept. of Computer Science, Engineering, and Math University of South Carolina Aiken, Aiken, SC 29801
Abstract:

Let \(G = (V(G), E(G))\) be a graph with minimum degree at least \(1\). The inverse degree of \(G\), denoted \(Id(G)\), is defined as the sum of the reciprocals of degrees of all vertices in \(G\). In this note, we present inverse degree conditions for Hamiltonian and traceable graphs.

Author(s): Johan Kok1
1Independent Mathematics Researcher, City of Tshwane, South Africa & Visiting Faculty at CHRIST (Deemed to be a University), Bangalore, India
Abstract:

This note presents some upper bounds for the size of the upper deg-centric grapg \(G_{ud}\) of a simple connected graph G. Amongst others, a result for graphs for which a compliant graph \(G\) has \(G_{ud} \cong \overline G\) is presented. Finally, results for size minimality in respect upper deg-centrication and minimum size of such graph \(G\) are presented.