GRAPHS RELATED TO DIAMETER AND CENTER
Acta mathematica Universitatis Comenianae, Tome 66 (1997) no. 1
Citer cet article
Voir la notice de l'article provenant de la source Comenius University
A graph is said to be an $L$-graph if all its paths of diametral length contain a central vertex of $G$. Using an earlier result we show that any graph can be embedded to an $L$-graph of radius a and diameter $b$, where $a\le b\le 2a$. We show that the known bounds of the number of edges and the maximum degree of the graphs of diameter $d\ge 2$ are sharp for $L$-graphs, too. Then we estimate the minimum degree of $L$-graphs. Finally we estimate the number of central vertices in $L$-graphs; all bounds are best possible.