Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-17T16:40:15.320Z Has data issue: false hasContentIssue false

First order properties on nowhere dense structures

Published online by Cambridge University Press:  12 March 2014

Jaroslav Nešetřil
Affiliation:
Department of Applied Mathematics and Institute of Theoretical Computer Science (ITI), Charles University, Malostranské Nám.25, 11800 Praha 1, Czech Republic. E-mail: nesetril@kam.ms.mff.cuni.cz
Patrice Ossona de Mendez
Affiliation:
Centre d'Analyse et de Mathématiques Sociales CNRS, UMR 8557, 54 BD Raspail, 75006 Paris, France. E-mail: pom@ehess.fr

Abstract

A set A of vertices of a graph G is called d-scattered in G if no two d-neighborhoods of (distinct) vertices of A intersect. In other words, A is d-scattered if no two distinct vertices of A have distance at most 2d. This notion was isolated in the context of finite model theory by Ajtai and Gurevich and recently it played a prominent role in the study of homomorphism preservation theorems for special classes of structures (such as minor closed classes). This in turn led to the notions of wide, almost wide and quasi-wide classes of graphs. It has been proved previously that minor closed classes and classes of graphs with locally forbidden minors are examples of such classes and thus (relativized) homomorphism preservation theorem holds for them. In this paper we show that (more general) classes with bounded expansion and (newly defined) classes with bounded local expansion and even (very general) nowhere dense classes are quasi wide. This not only strictly generalizes the previous results but it also provides new proofs and algorithms for some of the old results. It appears that bounded expansion and nowhere dense classes are perhaps a proper setting for investigation of wide-type classes as in several instances we obtain a structural characterization. This also puts classes of bounded expansion in the new context. Our motivation stems from finite dualities. As a corollary we obtain that any homomorphism closed first order definable property restricted to a bounded expansion class is a restricted duality.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 2010

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

REFERENCES

[AG87]Ajtai, M. and Gurevich, Y., Monotone versus positive, Journal of the ACM, vol. 34 (1987), pp. 10041015.CrossRefGoogle Scholar
[AG97]Alechina, N. and Gurevich, Y., Syntax vs. semantics on finite structures, Structures in logic and computer science (Mycielski, J., Rozenberg, G., and Salomaa, A., editors), Lecture Notes in Computer Science, vol. 1261, Springer, 1997, pp. 1433.CrossRefGoogle Scholar
[ADG05]Atserias, A., Dawar, A., and Grohe, M., Preservation under extensions on well-behaved finite structures, 32nd International Colloquium on Automata, Languages and Programming (ICALP), Lecture Notes in Computer Science, vol. 3580, Springer-Verlag, 2005, pp. 14371449.CrossRefGoogle Scholar
[ADK04]Atserias, A., Dawar, A., and Kolaitis, P.G., On preservation under homomorphisms and unions of conjunctive queries, Proceedings of the Twenty-third ACM SIGMOD-SIGACT-SIGART Symposium on Principles of Database Dystems, ACM Press, 2004, pp. 319329.CrossRefGoogle Scholar
[ADK06]Atserias, A., Dawar, A., and Kolaitis, P.G., On preservation under homomorphisms and unions of conjunctive queries, Journal of the ACM, vol. 53 (2006), pp. 208237.CrossRefGoogle Scholar
[Ber83]Berge, C., Graphes, troisième ed., Gauthier-Villars, Paris, 1983.Google Scholar
[Cou90]Courcelle, B., The monadic second-order logic of graphs I: recognizable sets of finite graphs, Information Computation, vol. 85 (1990), pp. 1275.CrossRefGoogle Scholar
[Daw07a]Dawar, A., Finite model theory on tame classes of structures, Mathematical Foundations of Computer Science 2007 (Kucera, L. and Kucera, A., editors), Lecture Notes in Computer Science, vol. 4708, Springer, 2007, pp. 212.CrossRefGoogle Scholar
[Daw07b]Dawar, A., On preservation theorems in finite model theory, 07 2007, invited talk at the 6th Panhellenic Logic Symposium — Volos, Greece.Google Scholar
[DGK07]Dawar, A., Grohe, M., and Kreutzer, S., Locally excluding a minor, Proc. 22nd IEEE Symp. on Logic in Computer Science, 2007.Google Scholar
[Dvo07]Dvořák, Z., Asymptotical structure of combinatorial objects, Ph.D. thesis, Charles University, Faculty of Mathematics and Physics, 2007.Google Scholar
[Dvo08]Dvořák, Z., On forbidden subdivision characterizations of graph classes, European Journal of ombinatorics, vol. 29 (2008), no. 5, pp. 13211332.CrossRefGoogle Scholar
[EF96]Ebbinghaus, H.-D. and Flum, J., Finite model theory, Springer-Verlag, 1996.Google Scholar
[Gur84]Gurevich, Y., Toward logic tailored for computational complexity, Computation and proof theory (Richter, M. M.et al., editor), Lecture Notes in Mathematics, Springer-Verlag, 1984.Google Scholar
[HN04]Hell, P. and Nešetřil, J., Graphs and homomorphisms, Oxford Lecture Series in Mathematics and its Applications, vol. 28, Oxford University Press, 2004.CrossRefGoogle Scholar
[Hod93]Hodges, W., Model theory, Cambridge University Press, 1993.CrossRefGoogle Scholar
[KS99]Kreidler, M. and Seese, D., Monadic NP and graph minors, Computer Science Logic, Lecture Notes in Computer Science, no. 1584, Springer, 1999, pp. 126141.CrossRefGoogle Scholar
[Lib04]Libkin, L., Elements of finite model theory, Springer-Verlag, 2004.CrossRefGoogle Scholar
[Lyn59]Lyndon, R.C., Properties preserved under homomorphism, Pacific Journal of Mathematics, vol. 9 (1959), pp. 129142.CrossRefGoogle Scholar
[NOdM05a]Nešetřil, J. and de Mendez, P. Ossona, Aspects algorithmiques des classes d'expansion bornée, 7e Journées Graphes et Algorithmes (LaBRI — Université Bordeaux I) (L. Esperet, editor), vol. 1372–05, 2005, pp. 5558.Google Scholar
[NOdM05b]Nešetřil, J. and de Mendez, P. Ossona, The grad of a graph and classes with bounded expansion, 7th International Colloquium on Graph Theory (Raspaud, André and Delmas, Olivier, editors), Electronic Notes in Discrete Mathematics, vol. 22, Elsevier, 2005, pp. 101106.Google Scholar
[NOdM06a]Nešetřil, J. and de Mendez, P. Ossona, Linear time low tree-width partitions and algorithmic consequences, STOC'06. Proceedings of the 38th Annual ACM Symposium on Theory of Computing, ACM Press, 2006, pp. 391400.Google Scholar
[NOdM06b]Nešetřil, J. and de Mendez, P. Ossona, Low tree-depth partitions of classes with bounded expansion, Midsummer Combinatorial Workshop 2005 and DIMACS, DIMATIA, Rényi Workshop 2005 (Kara, Jan, editor), KAM Series, vol. 2006–770, 2006, pp. 7681.Google Scholar
[NOdM07]Nešetřil, J. and de Mendez, P. Ossona, Fraternal augmentations of graphs, coloration and minors, Proceedings of the Sixth Czech-Slovak International Symposium on Combinatorics, Graph Theory, Algorithms and Applications, Electronic Notes in Discrete Mathematics, vol. 28, 2007, pp. 223230.Google Scholar
[NOdM08a]Nešetřil, J. and de Mendez, P. Ossona, Grad and classes with bounded expansion I. Decompositions, European Journal of Combinatorics, vol. 29 (2008), no. 3, pp. 760776.CrossRefGoogle Scholar
[NOdM08b]Nešetřil, J. and de Mendez, P. Ossona, Grad and classes with bounded expansion II. Algorithmic aspects, European Journal of Combinatorics, vol. 29 (2008), no. 3, pp. 777791.CrossRefGoogle Scholar
[NOdM08c]Nešetřil, J. and de Mendez, P. Ossona, Grad and classes with bounded expansion III. Restricted graph homomorphism dualities, European Journal of Combinatorics, vol. 29 (2008), no. 4, pp. 10121024.CrossRefGoogle Scholar
[NOdM08d]Nešetřil, J. and de Mendez, P. Ossona, On nowhere dense graphs, European Journal of Combinatorics, (2008), submit-ted.Google Scholar
[NOdM08e]Nešetřil, J. and de Mendez, P. Ossona, Structural properties of sparse graphs, Building bridges between mathematics and computer science (Grötschel, Martin and Katona, Gyula O.H., editors), Bolyai Society Mathematical Studies, vol. 19, Springer, 2008, Edited in honor of L. Lovasz on his 60th birthday.Google Scholar
[NOdM09a]Nešetřil, J. and de Mendez, P. Ossona, Counting homomorphisms to sparse graphs, European Conference on Combinatorics, Graph Theory and Applications (EuroComb 2009), vol. 34, Electronic Notes in Discrete Mathematics, no. 1, Elsevier, 2009, pp. 393397.Google Scholar
[NOdM09b]Nešetřil, J. and de Mendez, P. Ossona, Counting subgraphs in graphs, in preparation, 2009.Google Scholar
[NOdM09c]Nešetřil, J. and de Mendez, P. Ossona, From sparse graphs to nowhere dense structures: Decompositions, independence, dualities and limits, Proc. of the fifth European Congress of Mathematics, 2009, submitted.Google Scholar
[NOdMW09]Nešetřil, J., de Mendez, P. Ossona, and Wood, D.R., Characterizations and examples of graph classes with bounded expansion, European Journal of Combinatorics, (2009), submitted.Google Scholar
[NT00]Nešetřil, J. and Tardif, C., Duality theorems for finite structures (characterizing gaps and good characterizations), Journal of Combinatorial Theory, Series B, vol. 80 (2000), pp. 8097.CrossRefGoogle Scholar
[NT05]Nešetřil, J. and Tardif, C., Short answers to exponentially long questions: Extremal aspects of homomorphism duality, SIAM Journal of Discrete Mathematics, vol. 19 (2005), no. 4, pp. 914920.CrossRefGoogle Scholar
[PRS94]Plotkin, S., Rao, S., and Smith, W.D., Shallow excluded minors and improved graph decomposition, 5th Symp. Discrete Algorithms. SIAM, 1994.Google Scholar
[Ros08]Rossman, B., Homomorphism preservation theorems, Journal of the ACM, vol. 55 (2008), no. 3, pp. 153.CrossRefGoogle Scholar
[Sto95]Stolboushkin, A., Finite monotone properties, Proc. 10th IEEE Symp. on Logic in Computer Science, 1995, pp. 324330.Google Scholar
[Tai59]Tait, W., A counterexample to a conjecture of Scott and Suppes, this Journal, vol. 24 (1959), pp. 1516.Google Scholar
[Zhu08]Zhu, X., Colouring graphs with bounded generalized colouring number, Discrete Mathematics, in press.Google Scholar