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Indestructible colourings and rainbow Ramsey theorems

Lajos Soukup (2009)

Fundamenta Mathematicae

We show that if a colouring c establishes ω₂ ↛ [(ω₁:ω)]² then c establishes this negative partition relation in each Cohen-generic extension of the ground model, i.e. this property of c is Cohen-indestructible. This result yields a negative answer to a question of Erdős and Hajnal: it is consistent that GCH holds and there is a colouring c:[ω₂]² → 2 establishing ω₂ ↛ [(ω₁:ω)]₂ such that some colouring g:[ω₁]² → 2 does not embed into c. It is also consistent that 2 ω is arbitrarily large, and there...

k -Ramsey classes and dimensions of graphs

Jan Kratochvíl (1995)

Commentationes Mathematicae Universitatis Carolinae

In this note, we introduce the notion of k -Ramsey classes of graphs and we reveal connections to intersection dimensions of graphs.

Limit distributions for multitype branching processes of m -ary search trees

Brigitte Chauvin, Quansheng Liu, Nicolas Pouyanne (2014)

Annales de l'I.H.P. Probabilités et statistiques

Let m 3 be an integer. The so-called m -ary search treeis a discrete time Markov chain which is very popular in theoretical computer science, modelling famous algorithms used in searching and sorting. This random process satisfies a well-known phase transition: when m 26 , the asymptotic behavior of the process is Gaussian, but for m 27 it is no longer Gaussian and a limit W D T of a complex-valued martingale arises. In this paper, we consider the multitype branching process which is the continuous time version...

Macaulay posets.

Bezrukov, Sergei L., Leck, Uwe (2004)

The Electronic Journal of Combinatorics [electronic only]

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