Date: Wednesday, June 4, 2025.
Venue: Online Via Zoom
Speaker: Prof. Jörg Koppitz from the Institute of Mathematics and Informatics, Bulgarian Academy of Sciences,
“On Endomorphisms of Finite Star Graphs”
The event was opened by Prof. Yeni Susanti, who gave a brief introduction and highlighted some key topics in graph theory to provide context for the talk. Prof. Koppitz began by explaining the definition of a simple graph, then introduced the concept of endomorphisms on simple graphs and their classification. He extended these ideas to finite star graphs. He presented some classifications of endomorphisms on star graphs, namely wEndS_n, sEndS_n, and EndS_n, each capturing different structural properties.
He continued by discussing the generating sets of the endomorphism monoid of a finite star graph and explained how to determine the rank of these sets.
In the final part of his presentation, Prof. Koppitz shared an important result about the algebraic presentation of the endomorphism monoid of a finite star graph, offering a clearer understanding of its structure. The talk was informative and valuable for students and researchers interested in algebra and graph theory.