Hostname: page-component-cd9895bd7-lnqnp Total loading time: 0 Render date: 2024-12-23T13:37:50.668Z Has data issue: false hasContentIssue false

Sizes of Induced Subgraphs of Ramsey Graphs

Published online by Cambridge University Press:  01 July 2009

NOGA ALON
Affiliation:
Tel Aviv University, Tel Aviv 69978, Israel and IAS, Princeton, NJ, 08540, USA (e-mail: [email protected])
JÓZSEF BALOGH
Affiliation:
Department of Mathematics, University of Illinois, Urbana, IL 61801, USA (e-mail: [email protected])
ALEXANDR KOSTOCHKA
Affiliation:
Department of Mathematics, University of Illinois, Urbana, IL 61801, USA and Sobolev Institute of Mathematics, Novosibirsk, Russia (e-mail: [email protected])
WOJCIECH SAMOTIJ
Affiliation:
Department of Mathematics, University of Illinois, Urbana, IL 61801, USA (e-mail: [email protected])

Abstract

An n-vertex graph G is c-Ramsey if it contains neither a complete nor an empty induced subgraph of size greater than c log n. Erdős, Faudree and Sós conjectured that every c-Ramsey graph with n vertices contains Ω(n5/2) induced subgraphs, any two of which differ either in the number of vertices or in the number of edges, i.e., the number of distinct pairs (|V(H)|, |E(H)|), as H ranges over all induced subgraphs of G, is Ω(n5/2). We prove an Ω(n2.3693) lower bound.

Type
Paper
Copyright
Copyright © Cambridge University Press 2009

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 Gutin, G. (1997) Properly colored Hamilton cycles in edge-colored complete graphs. Random Struct. Alg. 11 179186.3.0.CO;2-P>CrossRefGoogle Scholar
[2]Alon, N. and Kostochka, A. (2009) Induced subgraphs with distinct sizes. Random Struct. Alg. 34 4553.CrossRefGoogle Scholar
[3]Alon, N., Krivelevich, M. and Sudakov, B. (2003) Induced subgraphs of prescribed size. J. Graph Theory 43 239251.CrossRefGoogle Scholar
[4]Alon, N. and Spencer, J. (2000) The Probabilistic Method, 2nd edn, Wiley.CrossRefGoogle Scholar
[5]Bollobás, B. and Scott, A. D. (2006) Discrepancy in graphs and hypergraphs. Bolyai Soc. Math. Studies 15 3356.CrossRefGoogle Scholar
[6]Bukh, B. and Sudakov, B. (2007) Induced subgraphs of Ramsey graphs with many distinct degrees. J. Combin. Theory Ser. B 97 612619.CrossRefGoogle Scholar
[7]Erdős, P. (1992) Some of my favorite problems in various branches of combinatorics. Matematiche (Catania) 47 231240.Google Scholar
[8]Erdős, P. (1997) Some recent problems and results in graph theory. In The Second Kraków Conference on Graph Theory (Zgorzelisko, 1994), Discrete Math. 164 8185.CrossRefGoogle Scholar
[9]Erdős, P., Goldberg, M., Pach, J. and Spencer, J. (1988) Cutting a graph into two dissimilar halves. J. Graph Theory 2 121131.CrossRefGoogle Scholar
[10]Erdős, P. and Hajnal, A. (1977) On spanned subgraphs of graphs. In Contributions to Graph Theory and its Applications (Internat. Colloq., Oberhof, 1977), pp. 80–96.Google Scholar
[11]Erdős, P. and Szemerédi, E. (1972) On a Ramsey type theorem. In Collection of Articles Dedicated to the Memory of A. Rényi, Vol. I, Period. Math. Hungar. 2 295299.CrossRefGoogle Scholar
[12]Prömel, H. J. and Rödl, V. (1999) Non-Ramsey graphs are c log n-universal. J. Combin. Theory Ser. A 88 379384.CrossRefGoogle Scholar
[13]Shelah, S. (1998) Erdős and Rényi conjecture. J. Combin. Theory Ser. A 82 179185.CrossRefGoogle Scholar