Skip to main content
Log in

On the Convexity Number of Graphs

  • Original Paper
  • Published:
Graphs and Combinatorics Aims and scope Submit manuscript

Abstract

A set of vertices S in a graph is convex if it contains all vertices which belong to shortest paths between vertices in S. The convexity number c(G) of a graph G is the maximum cardinality of a convex set of vertices which does not contain all vertices of G. We prove NP-completeness of the problem to decide for a given bipartite graph G and an integer k whether c(G) ≥ k. Furthermore, we identify natural necessary extension properties of graphs of small convexity number and study the interplay between these properties and upper bounds on the convexity number.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Brandstädt, A., Le, V.B., Spinrad, J.P.: Graph classes: a survey. Siam Monogr. Discret. Math. (1999)

  2. Cáceres J., Márquez A., Oellermann O.R., Puertas M.L.: Rebuilding convex sets in graphs. Discret. Math. 297, 26–37 (2005)

    Article  MATH  Google Scholar 

  3. Canoy S.R. Jr., Garces I.J.L.: Convex sets under some graph operations. Graphs Comb. 4, 787–793 (2002)

    Article  MathSciNet  Google Scholar 

  4. Chartrand G., Wall C.E., Zhang P.: The convexity number of a graph. Graphs Comb. 18, 209–217 (2002)

    Article  MathSciNet  MATH  Google Scholar 

  5. Edelman P.H., Jamison R.E.: The theory of convex geometries. Geom. Dedicata. 19, 247–270 (1985)

    Article  MathSciNet  MATH  Google Scholar 

  6. Farber M., Jamison R.E.: Convexity in graphs and hypergraphs. SIAM J. Algebraic Discret. Methods 7, 433–444 (1986)

    Article  MathSciNet  MATH  Google Scholar 

  7. Garey M.R., Johnson D.S.: Computers and Intractability: A Guide to the Theory of NP-completeness. W.H. Freeman, New York (1979)

    MATH  Google Scholar 

  8. Gimbel J.G.: Some remarks on the convexity number of a graph. Graphs Comb. 19, 357–361 (2003)

    Article  MathSciNet  MATH  Google Scholar 

  9. Harary F., Nieminen J.: Convexity in graphs. J. Differ. Geom. 16, 185–190 (1981)

    MathSciNet  MATH  Google Scholar 

  10. Kim B.K.: A lower bound for the convexity number of some graphs. J. Appl. Math. Comput. 14, 185–191 (2003)

    Article  MATH  Google Scholar 

  11. McConnell, R.M., Spinrad, J.P.: Linear-time modular decomposition and efficient transitive orientation of comparability graphs. In: Proceedings of the Fifth Annual ACM-SIAM Symposium on Discrete Algorithms, pp. 536–545 (1994)

  12. McConnell R.M., Spinrad J.P.: Ordered vertex partitioning. Discret. Math. Theor. Comput. Sci. 4, 45–60 (2000)

    MathSciNet  MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Mitre C. Dourado.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Dourado, M.C., Protti, F., Rautenbach, D. et al. On the Convexity Number of Graphs. Graphs and Combinatorics 28, 333–345 (2012). https://doi.org/10.1007/s00373-011-1049-7

Download citation

  • Received:

  • Revised:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00373-011-1049-7

Keywords

Navigation