Generalized stepwise irregular graphs: graph operations and construction of $3$-SI graphs

Document Type : Full Length Article

Authors

Department of Mathematics and Computer Sciences, Hakim Sabzevari University, Sabzevar, Iran.

Abstract

Generalized stepwise irregular (GSI) graphs are graphs in which the degree difference between every pair of adjacent vertices is positive constant. Specifically, a graph $G $ is called a $ k $-stepwise irregular ( k -SI) graph if $|d_G(u)-d_G(v)|=k$ for each edge $uv \in E(G) $. In this paper, We examine the behavior of GSI graphs under some graph operations, such as sum, corona product, complement, subdivision, line graph, and vertex deletion. An Infinite family of $ 3$-SI graphs with a given cyclomatic number and distinct cycles are constructed. Further, a lower bound on the size of the unicyclic $3$-SI graphs is proposed.

Graphical Abstract

Generalized stepwise irregular graphs: graph operations and construction of $3$-SI graphs

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Main Subjects


Volume 11, Issue 1
March 2026
Pages 33-42
  • Receive Date: 19 August 2025
  • Revise Date: 11 November 2025
  • Accept Date: 15 November 2025
  • First Publish Date: 30 January 2026
  • Publish Date: 01 March 2026