On the total forcing number of a graph

Autor: Michael A. Henning, Randy Davila
Rok vydání: 2019
Předmět:
Zdroj: Discrete Applied Mathematics. 257:115-127
ISSN: 0166-218X
DOI: 10.1016/j.dam.2018.09.001
Popis: A total forcing set in a graph G is a forcing set (zero forcing set) in G which induces a subgraph without isolated vertices. Total forcing sets were introduced and first studied by Davila (2015). The total forcing number of G , denoted F t ( G ) is the minimum cardinality of a total forcing set in G . We study basic properties of F t ( G ) , relate F t ( G ) to various domination parameters, and establish N P -completeness of the associated decision problem for F t ( G ) . Our main contribution is to prove that if G is a connected graph of order n ≥ 3 with maximum degree Δ , then F t ( G ) ≤ ( Δ Δ + 1 ) n , with equality if and only if G is a complete graph K Δ + 1 , or a star K 1 , Δ .
Databáze: OpenAIRE