1 research outputs found
Extremal incomplete sets in finite abelian groups
Let be a finite abelian group. The critical number of
is the least positive integer such that every subset of cardinality at least spans , i.e., every element
of can be written as a nonempty sum of distinct elements of . The exact
values of the critical number have been completely determined recently for all
finite abelian groups. The structure of these sets of cardinality which fail to span has also been characterized except for the
case that is an even number and the case that with are
primes. In this paper, we characterize these extremal subsets for
is an even number, or with are primes and .Comment: Swith some notations into ones which are more popular and put the
materials of Appendix into the body. The present version is to appear in Ars
Combinatori