In 1993 Voloshin introduced the concept of mixed hypergraph. A mixed hypergraph is characterised by the fact that it possesses anti-edges as well as edges. In a colouring of a mixed hypergraph, every anti-edge has at least two vertices of the same colour. In this paper a new parameter is introduced: the monochromatic block number mb. It is the number of monochromatic blocks in a colouring of a Steiner system. The exact value of mb is given for every colouring in STS(upsilon). Upper and lower bounds for mb in particular SQSs are found.
The monochromatic block number
MILAZZO, Lorenzo Maria Filippo
1997-01-01
Abstract
In 1993 Voloshin introduced the concept of mixed hypergraph. A mixed hypergraph is characterised by the fact that it possesses anti-edges as well as edges. In a colouring of a mixed hypergraph, every anti-edge has at least two vertices of the same colour. In this paper a new parameter is introduced: the monochromatic block number mb. It is the number of monochromatic blocks in a colouring of a Steiner system. The exact value of mb is given for every colouring in STS(upsilon). Upper and lower bounds for mb in particular SQSs are found.File in questo prodotto:
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