Sombor index of directed graphs

Let be a digraph with set of arcs . The Sombor index of is defined as () = 1 2 ∑ ∈ √( + )2 + ( − )2 , where + and − are the out-degree and in-degree of the vertices and of . When is a graph, we recover the Sombor index of graphs, a molecular descriptor recently introduced with a good predictive pote...

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Autores:
Rada Rincón, Juan Pablo
Cruz Rodes, Roberto
Monsalve Aristizabal, Juan Daniel
Tipo de recurso:
Article of investigation
Fecha de publicación:
2022
Institución:
Universidad de Antioquia
Repositorio:
Repositorio UdeA
Idioma:
eng
OAI Identifier:
oai:bibliotecadigital.udea.edu.co:10495/46346
Acceso en línea:
https://hdl.handle.net/10495/46346
Palabra clave:
Álgebras operadores de vértices
Vertex operator algebras
Teoría de grafos
Graph theory
Teoría de conjuntos
Set theory
Índice de Sombor
Sombor index
http://id.loc.gov/authorities/subjects/sh88005699
Rights
openAccess
License
http://creativecommons.org/licenses/by-nc-nd/4.0/
Description
Summary:Let be a digraph with set of arcs . The Sombor index of is defined as () = 1 2 ∑ ∈ √( + )2 + ( − )2 , where + and − are the out-degree and in-degree of the vertices and of . When is a graph, we recover the Sombor index of graphs, a molecular descriptor recently introduced with a good predictive potential and a great research activity this year. In this paper we initiate the study of the Sombor index of digraphs. Specifically, we find sharp upper and lower bounds for over the class of digraphs with non-isolated vertices, the classes and of connected and strongly connected digraphs on vertices, respectively, the class of oriented trees () with vertices, and the class () of orientations of a fixed graph .