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











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












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















active

oldest

votes











Your Answer





StackExchange.ifUsing("editor", function () {
return StackExchange.using("mathjaxEditing", function () {
StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix) {
StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
});
});
}, "mathjax-editing");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "69"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
noCode: true, onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});














 

draft saved


draft discarded


















StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2996545%2fgraphs-with-operatornamediamg-2-operatornameradg%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown






























active

oldest

votes













active

oldest

votes









active

oldest

votes






active

oldest

votes
















 

draft saved


draft discarded



















































 


draft saved


draft discarded














StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2996545%2fgraphs-with-operatornamediamg-2-operatornameradg%23new-answer', 'question_page');
}
);

Post as a guest















Required, but never shown





















































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown

































Required, but never shown














Required, but never shown












Required, but never shown







Required, but never shown







Popular posts from this blog

Probability when a professor distributes a quiz and homework assignment to a class of n students.

Aardman Animations

Are they similar matrix