Monochromatic triangle - graph coloring












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I'm trying to find the smallest $n_c$ for which the problem of proving a complete graph with $n$ vertices with edges colored with $c$ colors has a monochromatic triangle could be simplified to a problem of proving the same for a smaller graph of $m_{c-1} < n$ vertices and $c-1$ colors using the Pigeonhole principle. $n$ should be a function of $c$.



This is similar to how the problem of proving that in a graph with 17 vertices where the edges are colored with 3 colors we could find a triangle can be simplified to proving that in a complete graph with 6 vertices and 2 colors there is a monochromatic triangle. Appreciate any help you could provide!










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  • $begingroup$
    Using such methods stops giving tight bounds quickly. This is confirmed by the partial results on various Ramsey numbers.
    $endgroup$
    – Zachary Hunter
    Jan 6 at 19:22










  • $begingroup$
    my answer at: math.stackexchange.com/questions/935143/… shows all $K_6$ actually have 2 monchromatic triangles in 2 colors, only 3 colorings of higher $K_n$ that force both to break, need be considered.
    $endgroup$
    – Roddy MacPhee
    Mar 7 at 19:45
















1












$begingroup$


I'm trying to find the smallest $n_c$ for which the problem of proving a complete graph with $n$ vertices with edges colored with $c$ colors has a monochromatic triangle could be simplified to a problem of proving the same for a smaller graph of $m_{c-1} < n$ vertices and $c-1$ colors using the Pigeonhole principle. $n$ should be a function of $c$.



This is similar to how the problem of proving that in a graph with 17 vertices where the edges are colored with 3 colors we could find a triangle can be simplified to proving that in a complete graph with 6 vertices and 2 colors there is a monochromatic triangle. Appreciate any help you could provide!










share|cite|improve this question











$endgroup$












  • $begingroup$
    Using such methods stops giving tight bounds quickly. This is confirmed by the partial results on various Ramsey numbers.
    $endgroup$
    – Zachary Hunter
    Jan 6 at 19:22










  • $begingroup$
    my answer at: math.stackexchange.com/questions/935143/… shows all $K_6$ actually have 2 monchromatic triangles in 2 colors, only 3 colorings of higher $K_n$ that force both to break, need be considered.
    $endgroup$
    – Roddy MacPhee
    Mar 7 at 19:45














1












1








1





$begingroup$


I'm trying to find the smallest $n_c$ for which the problem of proving a complete graph with $n$ vertices with edges colored with $c$ colors has a monochromatic triangle could be simplified to a problem of proving the same for a smaller graph of $m_{c-1} < n$ vertices and $c-1$ colors using the Pigeonhole principle. $n$ should be a function of $c$.



This is similar to how the problem of proving that in a graph with 17 vertices where the edges are colored with 3 colors we could find a triangle can be simplified to proving that in a complete graph with 6 vertices and 2 colors there is a monochromatic triangle. Appreciate any help you could provide!










share|cite|improve this question











$endgroup$




I'm trying to find the smallest $n_c$ for which the problem of proving a complete graph with $n$ vertices with edges colored with $c$ colors has a monochromatic triangle could be simplified to a problem of proving the same for a smaller graph of $m_{c-1} < n$ vertices and $c-1$ colors using the Pigeonhole principle. $n$ should be a function of $c$.



This is similar to how the problem of proving that in a graph with 17 vertices where the edges are colored with 3 colors we could find a triangle can be simplified to proving that in a complete graph with 6 vertices and 2 colors there is a monochromatic triangle. Appreciate any help you could provide!







graph-theory pigeonhole-principle coloring ramsey-theory






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share|cite|improve this question













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share|cite|improve this question








edited Jan 6 at 19:27







Matthew Larson

















asked Jan 6 at 19:11









Matthew LarsonMatthew Larson

366




366












  • $begingroup$
    Using such methods stops giving tight bounds quickly. This is confirmed by the partial results on various Ramsey numbers.
    $endgroup$
    – Zachary Hunter
    Jan 6 at 19:22










  • $begingroup$
    my answer at: math.stackexchange.com/questions/935143/… shows all $K_6$ actually have 2 monchromatic triangles in 2 colors, only 3 colorings of higher $K_n$ that force both to break, need be considered.
    $endgroup$
    – Roddy MacPhee
    Mar 7 at 19:45


















  • $begingroup$
    Using such methods stops giving tight bounds quickly. This is confirmed by the partial results on various Ramsey numbers.
    $endgroup$
    – Zachary Hunter
    Jan 6 at 19:22










  • $begingroup$
    my answer at: math.stackexchange.com/questions/935143/… shows all $K_6$ actually have 2 monchromatic triangles in 2 colors, only 3 colorings of higher $K_n$ that force both to break, need be considered.
    $endgroup$
    – Roddy MacPhee
    Mar 7 at 19:45
















$begingroup$
Using such methods stops giving tight bounds quickly. This is confirmed by the partial results on various Ramsey numbers.
$endgroup$
– Zachary Hunter
Jan 6 at 19:22




$begingroup$
Using such methods stops giving tight bounds quickly. This is confirmed by the partial results on various Ramsey numbers.
$endgroup$
– Zachary Hunter
Jan 6 at 19:22












$begingroup$
my answer at: math.stackexchange.com/questions/935143/… shows all $K_6$ actually have 2 monchromatic triangles in 2 colors, only 3 colorings of higher $K_n$ that force both to break, need be considered.
$endgroup$
– Roddy MacPhee
Mar 7 at 19:45




$begingroup$
my answer at: math.stackexchange.com/questions/935143/… shows all $K_6$ actually have 2 monchromatic triangles in 2 colors, only 3 colorings of higher $K_n$ that force both to break, need be considered.
$endgroup$
– Roddy MacPhee
Mar 7 at 19:45










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