43 research outputs found
Infinite Matroids and Determinacy of Games
Solving a problem of Diestel and Pott, we construct a large class of infinite
matroids. These can be used to provide counterexamples against the natural
extension of the Well-quasi-ordering-Conjecture to infinite matroids and to
show that the class of planar infinite matroids does not have a universal
matroid.
The existence of these matroids has a connection to Set Theory in that it
corresponds to the Determinacy of certain games. To show that our construction
gives matroids, we introduce a new very simple axiomatization of the class of
countable tame matroids