Ramsey theory refers to questions of the form "how many objects are needed to guarantee that a given property of the collection holds?"

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An upper bound for a graph Ramsey number

I am trying to prove the following result, given as an exercise in my book: $r(K_m+\bar{K_n},K_p+\bar{K_q})\le\binom{m+p-1}{m}n+\binom{m+p-1}{p}q$. Here $r(G,H)$ denotes the Ramsey number for the ...
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Prove that $r(k,k) + k \leq r(k + 1, k + 1) $

Prove that $r(k,k) + k \leq r(k + 1, k + 1)$, where $r(k,l)$ is the minimum number of vertexes in a Graph, where we have a clique with $k$ vertexes or a stable set with $l$ vertexes. There are ...
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What's the difference between Ramsey theory and Extremal graph theory?

Wikipedia teaches us that problems in Ramsey theory typically ask a question of the form: "how many elements of some structure must there be to guarantee that a particular property will hold?" It ...
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Closest pair of vectors in $\{0,1\}^n$

Suppose we are given $k$ points in $\{0,1\}^n$ (using Hamming distance as metric). Consider the two points that have the smallest distance between them. Does there exist any results bounding this ...
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Edge coloring a graph to find a monochromatic $K_{2,n}$

I am trying to prove or disprove the following statement: Let $n>1$ be a positive integer. Then there exists a graph $G$ of size 4n-1 such that if the edges of $G$ are colored red or blue, no ...
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Known bounds and values for Ramsey Numbers

Is there a good online reference that lists known bounds on Ramsey numbers (and is relatively up to date)? The wikipedia page only has numbers for $R_2(n,m)$. I am specifically interested in known ...
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A “geometrical” representation for Ramsey's theorem

The [infinite] Ramsey theorem states that Let $n$ and $k$ be natural numbers. Every partition $\{X_1,\ldots ,X_k\}$ of $[\omega]^n$ into $k$ pieces has an infinite homogeneous set. Equivalently, ...
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how to construct 17-vertexed graph for Ramsey number R(3,6)=18

Ramsey number $R(3,6)=18$. How to construct a graph of $17$ nodes which does not contain neither a clique of order $3$ or an independent set of order $6$. could you show me the tactics or the ...