Graphs with $operatorname{diam}(G)=2operatorname{rad}(G)$











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When is the diameter of a graph equal to twice of radius? I am currently studying graph theory and have faced many questions related to graphs with the mentioned property. Is there any general class of graphs which follow this property?



I know path graphs with odd vertices are such graphs, but is there a more general graph?










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    A tree has this property if and only if it has a center vertex. By a center vertex, I mean, consider iteratively removing leaves, i.e. at step one, remove all leaves, then at step 2 repeat. In a tree, you'll either be left with an edge or with a vertex. If you're left with a vertex, then that's called the center vertex of the tree. You can quickly check that a center vertex of a tree is exactly the realizer that $diam(G)=2rad(G)$.
    – munchhausen
    Nov 13 at 18:00















up vote
1
down vote

favorite












When is the diameter of a graph equal to twice of radius? I am currently studying graph theory and have faced many questions related to graphs with the mentioned property. Is there any general class of graphs which follow this property?



I know path graphs with odd vertices are such graphs, but is there a more general graph?










share|cite|improve this question




















  • 1




    A tree has this property if and only if it has a center vertex. By a center vertex, I mean, consider iteratively removing leaves, i.e. at step one, remove all leaves, then at step 2 repeat. In a tree, you'll either be left with an edge or with a vertex. If you're left with a vertex, then that's called the center vertex of the tree. You can quickly check that a center vertex of a tree is exactly the realizer that $diam(G)=2rad(G)$.
    – munchhausen
    Nov 13 at 18:00













up vote
1
down vote

favorite









up vote
1
down vote

favorite











When is the diameter of a graph equal to twice of radius? I am currently studying graph theory and have faced many questions related to graphs with the mentioned property. Is there any general class of graphs which follow this property?



I know path graphs with odd vertices are such graphs, but is there a more general graph?










share|cite|improve this question















When is the diameter of a graph equal to twice of radius? I am currently studying graph theory and have faced many questions related to graphs with the mentioned property. Is there any general class of graphs which follow this property?



I know path graphs with odd vertices are such graphs, but is there a more general graph?







graph-theory






share|cite|improve this question















share|cite|improve this question













share|cite|improve this question




share|cite|improve this question








edited Nov 13 at 10:40









Bernard

115k637108




115k637108










asked Nov 13 at 9:58









Ankit Kumar

32510




32510








  • 1




    A tree has this property if and only if it has a center vertex. By a center vertex, I mean, consider iteratively removing leaves, i.e. at step one, remove all leaves, then at step 2 repeat. In a tree, you'll either be left with an edge or with a vertex. If you're left with a vertex, then that's called the center vertex of the tree. You can quickly check that a center vertex of a tree is exactly the realizer that $diam(G)=2rad(G)$.
    – munchhausen
    Nov 13 at 18:00














  • 1




    A tree has this property if and only if it has a center vertex. By a center vertex, I mean, consider iteratively removing leaves, i.e. at step one, remove all leaves, then at step 2 repeat. In a tree, you'll either be left with an edge or with a vertex. If you're left with a vertex, then that's called the center vertex of the tree. You can quickly check that a center vertex of a tree is exactly the realizer that $diam(G)=2rad(G)$.
    – munchhausen
    Nov 13 at 18:00








1




1




A tree has this property if and only if it has a center vertex. By a center vertex, I mean, consider iteratively removing leaves, i.e. at step one, remove all leaves, then at step 2 repeat. In a tree, you'll either be left with an edge or with a vertex. If you're left with a vertex, then that's called the center vertex of the tree. You can quickly check that a center vertex of a tree is exactly the realizer that $diam(G)=2rad(G)$.
– munchhausen
Nov 13 at 18:00




A tree has this property if and only if it has a center vertex. By a center vertex, I mean, consider iteratively removing leaves, i.e. at step one, remove all leaves, then at step 2 repeat. In a tree, you'll either be left with an edge or with a vertex. If you're left with a vertex, then that's called the center vertex of the tree. You can quickly check that a center vertex of a tree is exactly the realizer that $diam(G)=2rad(G)$.
– munchhausen
Nov 13 at 18:00















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