On the hull-variation problem of equivalent vector rank metric codes

The intersection of a linear code with its dual is called the hull of the code. It is known that, for classical linear codes under the Hamming metric, the dimension of the hull can be reduced up to equivalence. This phenomenon leads to the so-called hull-variation problem formulated by Hao Chen in 2023. In this paper, we consider the analogous problem for vector rank metric codes, along with their associated matrix codes and extended block codes. We also discuss the implications in the context of $(q,m)$-polymatroids.