Skip to main content
Log in

t-expansive andt-wise intersecting hypergraphs

  • Published:
Graphs and Combinatorics Aims and scope Submit manuscript

Abstract

We give a hypergraph generalization of Gallai's theorem about factor-critical graphs. This result can be used to determineτ *(r, t) forr < 3t/2, whereτ *(r, t) denotes the maximum value of the fractional covering numbers oft-wise intersecting hypergraphs of rankr.

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.

Similar content being viewed by others

References

  1. Alon, N., Füredi, Z.: On the kernel of intersecting families.

  2. Bang, C., Sharp, H., Winkler, P.: On coverings of a finite set: depth and subcovers. Period. Math. Hung.15, 51–60 (1984)

    Google Scholar 

  3. Brace, A., Daykin, D.E.: Cover theorems for finite sets I–III. Bull. Aust. Math. Soc.5, 197–202 (1971),6, 19–24 (1972),6, 417–433 (1972)

    Google Scholar 

  4. Daykin, D.E.: Problem E 2654. Amer. Math. Mon.84, 386 (1977). Minimum subcover of a cover of a finite set (Problem E 2654). Amer. Math. Mon.85, 766 (1978)

    Google Scholar 

  5. Daykin, D.E., Frankl, P.: Sets of finite sets satisfying union conditions. Mathematica29, 128–134 (1982)

    Google Scholar 

  6. Edmonds, J.: Paths, trees, and flowers. Canad. J. Math.17, 449–467 (1965)

    Google Scholar 

  7. Erdös, P., Lovász, L.: Problems and results in 3-chromatic hypergraphs and some related questions. In: Infinite and Finite Sets. Colloq. Math. Soc. János Bolyai10, 609–627 (1975)

    Google Scholar 

  8. Erdös, P., Rado, R.: Intersection theorems for systems of sets. J. London Math. Soc.35, 85–90 (1960)

    Google Scholar 

  9. Frankl, P., Füredi, Z.: Finite projective spaces and intersecting hypergraphs. Combinatorica (to appear)

  10. Füredi, Z.: Maximum degree and fractional matchings in uniform hypergraphs. Combinatorica1, 155–162 (1981)

    Google Scholar 

  11. Gallai, T.: Neuer Beweis eines Tutte'shen Satzes. MTA Math. Kut. Int. Közl.8, 135–139 (1963)

    Google Scholar 

  12. Hanson, D., Toft, B.: On the maximum number of vertices inn-uniform cliques. Ars Comb.16-A, 205–216 (1983)

    Google Scholar 

  13. Lovász, L.: Combinatorial Problems and Exercises. Budapest: Akadémiai Kiadó/Amsterdam: North-Holland 1979

    Google Scholar 

  14. Lovász, L.: Doctoral Thesis. Szeged 1977. Also see: On minimax theorems of combinatorics (in Hungarian). Mat. Lapok26, 209–264 (1975)

    Google Scholar 

  15. Lovász, L.: Minimax theorems for hypergraphs. In: Hypergraph Seminar 1972, Lecture Notes in Mathematics 411, pp 111–126. Berlin-Heidelberg-New York: Springer-Verlag 1972

    Google Scholar 

  16. Meyer, J.-C.: Quelques problémes concernant les cliques des hypergraphsh-complets etq-partih-complets. In: Hypergraph Seminar 1972, Lecture Notes in Mathematics 411, pp 127–139. Berlin-Heidelberg-New York: Springer-Verlag 1974

    Google Scholar 

  17. Tuza, Z.: Critical hypergraphs and intersecting set-pair systems. J. Comb. Theory (B)39, 134–145 (1985)

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

Dedicated to Tibor Gallai

Rights and permissions

Reprints and permissions

About this article

Cite this article

Füredi, Z. t-expansive andt-wise intersecting hypergraphs. Graphs and Combinatorics 2, 67–80 (1986). https://doi.org/10.1007/BF01788079

Download citation

  • Received:

  • Revised:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01788079

Keywords

Navigation