q-Matroids form the q-analogue of classical matroids. In this paper we introduce various types of maps between q-matroids. These maps are not necessarily linear, but they map subspaces to subspaces and respect the q-matroid structure in certain ways. The various types of maps give rise to different categories of q-matroids. We show that only one of these categories possesses a coproduct. This is the category where the morphisms are linear weak maps, that is, the rank of the image of any subspace is not larger than the rank of the subspace itself. The coproduct in this category is the very recently introduced direct sum of q-matroids.

翻译：q-拟阵是经典拟阵的q-模拟。本文引入q-拟阵之间的多种映射类型。这些映射不必是线性的，但将子空间映射至子空间，并以特定方式保持q-拟阵结构。不同类型的映射衍生出不同的q-拟阵范畴。我们证明，仅有一类范畴具有余积。该范畴中态射为线性弱映射，即任意子空间像的秩不超过该子空间本身的秩。此范畴中的余积即为近期引入的q-拟阵直和。