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.
Similar content being viewed by others
References
Alon, N., Füredi, Z.: On the kernel of intersecting families.
Bang, C., Sharp, H., Winkler, P.: On coverings of a finite set: depth and subcovers. Period. Math. Hung.15, 51–60 (1984)
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)
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)
Daykin, D.E., Frankl, P.: Sets of finite sets satisfying union conditions. Mathematica29, 128–134 (1982)
Edmonds, J.: Paths, trees, and flowers. Canad. J. Math.17, 449–467 (1965)
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)
Erdös, P., Rado, R.: Intersection theorems for systems of sets. J. London Math. Soc.35, 85–90 (1960)
Frankl, P., Füredi, Z.: Finite projective spaces and intersecting hypergraphs. Combinatorica (to appear)
Füredi, Z.: Maximum degree and fractional matchings in uniform hypergraphs. Combinatorica1, 155–162 (1981)
Gallai, T.: Neuer Beweis eines Tutte'shen Satzes. MTA Math. Kut. Int. Közl.8, 135–139 (1963)
Hanson, D., Toft, B.: On the maximum number of vertices inn-uniform cliques. Ars Comb.16-A, 205–216 (1983)
Lovász, L.: Combinatorial Problems and Exercises. Budapest: Akadémiai Kiadó/Amsterdam: North-Holland 1979
Lovász, L.: Doctoral Thesis. Szeged 1977. Also see: On minimax theorems of combinatorics (in Hungarian). Mat. Lapok26, 209–264 (1975)
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
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
Tuza, Z.: Critical hypergraphs and intersecting set-pair systems. J. Comb. Theory (B)39, 134–145 (1985)
Author information
Authors and Affiliations
Additional information
Dedicated to Tibor Gallai
Rights 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
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01788079