# DMGT

ISSN 1234-3099 (print version)

ISSN 2083-5892 (electronic version)

# IMPACT FACTOR 2019: 0.755

SCImago Journal Rank (SJR) 2019: 0.600

Rejection Rate (2018-2019): c. 84%

# Discussiones Mathematicae Graph Theory

## COMPETITION HYPERGRAPHS OF DIGRAPHS WITH CERTAIN PROPERTIES I STRONG CONNECTEDNESS

 Martin Sonntag Faculty of Mathematics and Computer Science TU Bergakademie Freiberg Prüferstraße 1, D-09596 Freiberg, Germany e-mail: sonntag@mathe.tu-freiberg.de Hanns-Martin Teichert Institute of Mathematics University of Lübeck Wallstraß e 40, D-23560 Lübeck, Germany e-mail: teichert@math.uni-luebeck.de

## Abstract

If D = (V,A) is a digraph, its competition hypergraph CH(D) has the vertex set V and e ⊆ V is an edge of CH(D) iff |e| ≥ 2 and there is a vertex v ∈ V, such that e = {w ∈ V|(w,v) ∈ A}. We tackle the problem to minimize the number of strong components in D without changing the competition hypergraph CH(D). The results are closely related to the corresponding investigations for competition graphs in Fraughnaugh et al. [3].

Keywords: hypergraph, competition graph, strong component.

2000 Mathematics Subject Classification: 05C65, 05C20, 05C40.

## References

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