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A spanning bandwidth theorem in random graphs

Published online by Cambridge University Press:  13 December 2021

Peter Allen
Affiliation:
London School of Economics, Department of Mathematics, Houghton Street, London WC2A 2AE, UK
Julia Böttcher*
Affiliation:
London School of Economics, Department of Mathematics, Houghton Street, London WC2A 2AE, UK
Julia Ehrenmüller
Affiliation:
Technische Universität Hamburg, Institut fìr Mathematik, Am Schwarzenberg-Campus 3, 21073 Hamburg, Germany
Jakob Schnitzer
Affiliation:
Universität Hamburg, Fachbereich Mathematik, Bundesstrasse 55, 20146 HamburgGermany
Anusch Taraz
Affiliation:
Technische Universität Hamburg, Institut fìr Mathematik, Am Schwarzenberg-Campus 3, 21073 Hamburg, Germany
*
*Corresponding author. Email: [email protected]

Abstract

The bandwidth theorem of Böttcher, Schacht and Taraz states that any n-vertex graph G with minimum degree $\big(\tfrac{k-1}{k}+o(1)\big)n$ contains all n-vertex k-colourable graphs H with bounded maximum degree and bandwidth o(n). Recently, a subset of the authors proved a random graph analogue of this statement: for $p\gg \big(\tfrac{\log n}{n}\big)^{1/\Delta}$ a.a.s. each spanning subgraph G of G(n,p) with minimum degree $\big(\tfrac{k-1}{k}+o(1)\big)pn$ contains all n-vertex k-colourable graphs H with maximum degree $\Delta$ , bandwidth o(n), and at least $C p^{-2}$ vertices not contained in any triangle. This restriction on vertices in triangles is necessary, but limiting. In this paper, we consider how it can be avoided. A special case of our main result is that, under the same conditions, if additionally all vertex neighbourhoods in G contain many copies of $K_\Delta$ then we can drop the restriction on H that $Cp^{-2}$ vertices should not be in triangles.

MSC classification

Type
Paper
Copyright
© The Author(s), 2021. Published by Cambridge University Press

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References

Allen, P., Böttcher, J., Ehrenmüller, J. and Taraz, A. (2020) The bandwidth theorem in sparse graphs. Adv. Comb. Paper No. 6, 60.Google Scholar
Allen, P., Böttcher, J., Hàn, H., Kohayakawa, Y. and Person, Y. Blow-up lemmas for sparse graphs. Submitted, arXiv:1612.00622.Google Scholar
Böttcher, J. (2017) Large-scale structures in random graphs. In Surveys in Combinatorics 2017, Vol. 440 of London Mathematical Society Lecture Note Series, Cambridge University Press, Cambridge, pp. 87–140.CrossRefGoogle Scholar
Böttcher, J., Schacht, M. and Taraz, A. (2009) Proof of the bandwidth conjecture of BollobÁs and Komlós. Math. Ann. 343(1) 175205.CrossRefGoogle Scholar
Dirac, G. A. (1952) Some theorems on abstract graphs. Proc. London Math. Soc. (3) 2 6981.CrossRefGoogle Scholar
Fischer, M., Škorić, N., Steger, A. and Trujić, M. Triangle resilience of the square of a Hamilton cycle in random graphs. Submitted, arXiv:1809.07534.Google Scholar
Gerke, S., Kohayakawa, Y., Rödl, V. and Steger, A. (2007) Small subsets inherit sparse $\varepsilon$ -regularity. J. Comb. Theory Ser. B 97(1) 3456.CrossRefGoogle Scholar
Hajnal, A. and Szemerédi, E. (1970) Proof of a conjecture of P. Erdös. In Combinatorial Theory and its Applications, II (Proc. Colloq., Balatonfüred, 1969), pp. 601–623.Google Scholar
Janson, S., Łuczak, T. and Rucinski, A. (2000) Random Graphs. Wiley-Interscience Series in Discrete Mathematics and Optimization. Wiley-Interscience, New York.CrossRefGoogle Scholar
Kohayakawa, Y. (1997) Szemerédi’s regularity lemma for sparse graphs. In Foundations of Computational Mathematics (Rio de Janeiro, 1997), Springer, Berlin, pp. 216230.CrossRefGoogle Scholar
Kohayakawa, Y. and Rödl, V. (2003) Szemerédi’s regularity lemma and quasi-randomness. In Recent Advances in Algorithms and Combinatorics, Vol. 11 of CMS Books in Mathematics/Ouvrages Mathematics SMC, Springer, New York, pp. 289–351.CrossRefGoogle Scholar
Komlós, J., Sárközy, G. N. and Szemerédi, E. (1997) Blow-up lemma. Combinatorica 17(1) 109123.CrossRefGoogle Scholar
Komlós, J., Sárközy, G. N. and Szemerédi, E. (1998) Proof of the Seymour conjecture for large graphs. Ann. Comb. 2(1) 4360.CrossRefGoogle Scholar
Kühn, D. and Osthus, D. (2009) Embedding large subgraphs into dense graphs. In Surveys in Combinatorics 2009, Vol. 365 of London Mathematical Society Lecture Note Series, Cambridge University Press, Cambridge, pp. 137–167.CrossRefGoogle Scholar
Lee, C. and Sudakov, B. (2012) Dirac’s theorem for random graphs. Random Struct. Algorithms 41(3) 293305.10.1002/rsa.20419CrossRefGoogle Scholar
Scott, A. (2011) Szemerédi’s regularity lemma for matrices and sparse graphs. Comb. Probab. Comput. 20(3) 455466.CrossRefGoogle Scholar