What is the maximum connectivity of a planar graph?












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The Icosahedral Graph is a simple 5-connected planar graph. Is there a 6-connected planar graph?



In general, is there a theoretical maximum on the vertex connectivity of planar graphs? This is spurred since the number of edges is bounded by $3n-6$, and that could set an upper bound on the vertex connectivity.










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    A planar graph must have a vertex of degree less than six.
    $endgroup$
    – Gerry Myerson
    Dec 4 '18 at 22:57
















2












$begingroup$


The Icosahedral Graph is a simple 5-connected planar graph. Is there a 6-connected planar graph?



In general, is there a theoretical maximum on the vertex connectivity of planar graphs? This is spurred since the number of edges is bounded by $3n-6$, and that could set an upper bound on the vertex connectivity.










share|cite|improve this question









$endgroup$








  • 2




    $begingroup$
    A planar graph must have a vertex of degree less than six.
    $endgroup$
    – Gerry Myerson
    Dec 4 '18 at 22:57














2












2








2





$begingroup$


The Icosahedral Graph is a simple 5-connected planar graph. Is there a 6-connected planar graph?



In general, is there a theoretical maximum on the vertex connectivity of planar graphs? This is spurred since the number of edges is bounded by $3n-6$, and that could set an upper bound on the vertex connectivity.










share|cite|improve this question









$endgroup$




The Icosahedral Graph is a simple 5-connected planar graph. Is there a 6-connected planar graph?



In general, is there a theoretical maximum on the vertex connectivity of planar graphs? This is spurred since the number of edges is bounded by $3n-6$, and that could set an upper bound on the vertex connectivity.







graph-theory algorithms connectedness graph-connectivity






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asked Dec 4 '18 at 22:53









illigradilligrad

334




334








  • 2




    $begingroup$
    A planar graph must have a vertex of degree less than six.
    $endgroup$
    – Gerry Myerson
    Dec 4 '18 at 22:57














  • 2




    $begingroup$
    A planar graph must have a vertex of degree less than six.
    $endgroup$
    – Gerry Myerson
    Dec 4 '18 at 22:57








2




2




$begingroup$
A planar graph must have a vertex of degree less than six.
$endgroup$
– Gerry Myerson
Dec 4 '18 at 22:57




$begingroup$
A planar graph must have a vertex of degree less than six.
$endgroup$
– Gerry Myerson
Dec 4 '18 at 22:57










1 Answer
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3












$begingroup$

I think you pointed at the exact right direction.
As the number of edges is at most $3n-6$, there must be a vertex $v$ of degree at most $5$. Delete the neighbors of $v$, and the graph falls apart (unless it had at most 6 vertices).






share|cite|improve this answer











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    $begingroup$

    I think you pointed at the exact right direction.
    As the number of edges is at most $3n-6$, there must be a vertex $v$ of degree at most $5$. Delete the neighbors of $v$, and the graph falls apart (unless it had at most 6 vertices).






    share|cite|improve this answer











    $endgroup$


















      3












      $begingroup$

      I think you pointed at the exact right direction.
      As the number of edges is at most $3n-6$, there must be a vertex $v$ of degree at most $5$. Delete the neighbors of $v$, and the graph falls apart (unless it had at most 6 vertices).






      share|cite|improve this answer











      $endgroup$
















        3












        3








        3





        $begingroup$

        I think you pointed at the exact right direction.
        As the number of edges is at most $3n-6$, there must be a vertex $v$ of degree at most $5$. Delete the neighbors of $v$, and the graph falls apart (unless it had at most 6 vertices).






        share|cite|improve this answer











        $endgroup$



        I think you pointed at the exact right direction.
        As the number of edges is at most $3n-6$, there must be a vertex $v$ of degree at most $5$. Delete the neighbors of $v$, and the graph falls apart (unless it had at most 6 vertices).







        share|cite|improve this answer














        share|cite|improve this answer



        share|cite|improve this answer








        edited Dec 4 '18 at 23:02

























        answered Dec 4 '18 at 22:57









        A. PongráczA. Pongrácz

        5,9531929




        5,9531929






























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