Hostname: page-component-848d4c4894-4rdrl Total loading time: 0 Render date: 2024-06-28T07:56:05.774Z Has data issue: false hasContentIssue false

Colourings of Uniform Hypergraphs with Large Girth and Applications

Published online by Cambridge University Press:  09 October 2017

ANDREY KUPAVSKII
Affiliation:
Laboratory of Advanced Combinatorics and Network Applications, Moscow Institute of Physics and Technology, Moscow Region, Russia Ecole Polytechnique Fédérale de Lausanne, Switzerland (e-mail: kupavskii@ya.ru)
DMITRY SHABANOV
Affiliation:
Laboratory of Advanced Combinatorics and Network Applications, Moscow Institute of Physics and Technology, 141700, Institutskiy per. 9, Dolgoprudny, Moscow Region, Russia Faculty of Computer Science, National Research University Higher School of Economics (HSE), 101000, Myasnitskaya Str. 20, Moscow, Russia (e-mail: dm.shabanov.msu@gmail.com)

Abstract

This paper deals with a combinatorial problem concerning colourings of uniform hypergraphs with large girth. We prove that if H is an n-uniform non-r-colourable simple hypergraph then its maximum edge degree Δ(H) satisfies the inequality

$$ \Delta(H)\geqslant c\cdot r^{n-1}\ffrac{n(\ln\ln n)^2}{\ln n} $$
for some absolute constant c > 0.

As an application of our probabilistic technique we establish a lower bound for the classical van der Waerden number W(n, r), the minimum natural N such that in an arbitrary colouring of the set of integers {1,. . .,N} with r colours there exists a monochromatic arithmetic progression of length n. We prove that

$$ W(n,r)\geqslant c\cdot r^{n-1}\ffrac{(\ln\ln n)^2}{\ln n}. $$

Type
Paper
Copyright
Copyright © Cambridge University Press 2017 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Alon, N. and Spencer, J. H. (2008) The Probabilistic Method, third edition, Wiley.Google Scholar
[2] Beck, J. (1978) On 3-chromatic hypergraphs. Discrete Math. 24 127137.Google Scholar
[3] Berlekamp, E. (1968) A construction for partitions which avoid long arithmetic progressions. Canad. Math. Bull. 11 409414.Google Scholar
[4] Cherkashin, D. D. and Kozik, J. (2015) A note on random greedy coloring of uniform hypergraphs. Random Struct. Alg. 47 407416.Google Scholar
[5] Erdős, P. and Lovász, L. (1973) Problems and results on 3-chromatic hypergraphs and some related questions. In Infinite and Finite Sets, Vol. 10 of Colloquia Mathematica Societatis Janos Bolyai, North-Holland, pp. 609627.Google Scholar
[6] Erdős, P. and Radó, R. (1952) Combinatorial theorems on classifications of subsets of given set. Proc. London Math. Soc. 2 417439.Google Scholar
[7] Gowers, W. T. (2001) A new proof of Szemerédi's theorem. Geom. Funct. Anal. 11 465588.Google Scholar
[8] Graham, R. L., Rothschild, B. L. and Spencer, J. H. (1990) Ramsey Theory, second edition, Wiley.Google Scholar
[9] Green, B. and Tao, T. (2009) New bounds for Szemerédi's theorem II: A new bound for r 4(N). In Analytic Number Theory: Essays in Honour of Klaus Roth (Chen, W. et al., eds), Cambridge University Press, pp. 180204.Google Scholar
[10] Kostochka, A. V. and Kumbhat, M. (2009) Coloring uniform hypergraphs with few edges. Random Struct. Alg. 35 348368.CrossRefGoogle Scholar
[11] Kostochka, A. V., Kumbhat, M. and Rödl, V. (2010) Coloring uniform hypergraphs with small edge degrees. In Fete of Combinatorics and Computer Science, Vol. 20 of Bolyai Society Mathematical Studies, Springer, pp. 213238.CrossRefGoogle Scholar
[12] Kostochka, A. V. and Rödl, V. (2010) Constructions of sparse uniform hypergraphs with high chromatic number. Random Struct. Alg. 36 4656.Google Scholar
[13] Kozik, J. (2016) Multipass greedy coloring of simple uniform hypergraphs. Random Struct. Alg. 48 125146.Google Scholar
[14] Moser, L. (1960) On a theorem of van der Waerden. Canad. Math. Bull. 3 2325.Google Scholar
[15] O'Bryant, K. (2011) Sets of integers that do not contain long arithmetic progressions. Electron. J. Combin. 18 P59.Google Scholar
[16] Pluhár, A. (2009) Greedy colorings of uniform hypergraphs. Random Struct. Alg. 35 216221.CrossRefGoogle Scholar
[17] Radhakrishnan, J. and Srinivasan, A. (2000) Improved bounds and algorithms for hypergraph two-coloring. Random Struct. Alg. 16 432.Google Scholar
[18] Sanders, T. (2011) On Roth's theorem on progressions. Ann. of Math. 174 619636.CrossRefGoogle Scholar
[19] Schmidt, W. M. (1962) Two combinatorial theorems on arithmetic progressions. Duke Math. J. 29 129140.Google Scholar
[20] Shabanov, D. A. (2012) On r-chromatic hypergraphs. Discrete Math. 312 441458.Google Scholar
[21] Shabanov, D. A. (2012) Random coloring method in the combinatorial problem of Erdős and Lovász. Random Struct. Alg. 40 227253.Google Scholar
[22] Shabanov, D. A. (2011) Van der Waerden's function and colourings of hypergraphs. Izvestiya: Mathematics 75 10631091.CrossRefGoogle Scholar
[23] Spencer, J. H. (1981) Coloring n-sets red and blue. J. Combin. Theory Ser. A 30 112113.Google Scholar
[24] Szabó, Z. (1990) An application of Lovász' Local Lemma: A new lower bound for the van der Waerden number. Random Struct. Alg. 1 343360.Google Scholar
[25] van der Waerden, B. L. (1927) Beweis einer Baudetschen Vermutung. Nieuw Archief voor Wiskunde 15 212216.Google Scholar