Wolfgang Schmid (Université Paris 8) : Davenport constants, three sides of a coin

We discuss three definitions of a notion in additive combinatorics generally known as Davenport constant, which are equivalent in the classical context of zero-sum sequences over finite abelian groups.  

In related contexts such as zero-sum sequences restricted to subsets of (finite) abelian groups, weighted zero-sum sequences over finite abelian groups, or product one-sequences over finite groups, it turns out that two of the three definitions remain equivalent, yet the third one can be quite different. 

We present a few results on these constants in various contexts, focusing on the case of plus-minus weighted zero-sum sequences.