English

Singular Ramsey and Tur\'an numbers

Combinatorics 2019-01-29 v1

Abstract

We say that a subgraph FF of a graph GG is singular if the degrees dG(v)d_G(v) are all equal or all distinct for the vertices vV(F)v\in V(F). The singular Ramsey number Rs(F)(F) is the smallest positive integer nn such that, for every mnm\geq n, in every edge 2-coloring of KmK_m, at least one of the color classes contains FF as a singular subgraph. In a similar flavor, the singular Tur\'an number Ts(n,F)(n,F) is defined as the maximum number of edges in a graph of order nn, which does not contain FF as a singular subgraph. In this paper we initiate the study of these extremal problems. We develop methods to estimate Rs(F)(F) and Ts(n,F)(n,F), present tight asymptotic bounds and exact results.

Keywords

Cite

@article{arxiv.1901.09412,
  title  = {Singular Ramsey and Tur\'an numbers},
  author = {Yair Caro and Zsolt Tuza},
  journal= {arXiv preprint arXiv:1901.09412},
  year   = {2019}
}

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43 pages