In this paper we extend the theory of Rubio de Francia extrapolation for matrix weights, recently introduced by Bownik and the first author (2022), to off-diagonal extrapolation. We also show that the theory of matrix weighted extrapolation can be extended to matrix \ (Aₚ\) classes defined with respect to a general basis, provided that a version of the Christ–Goldberg maximal operator is assumed to be bounded. Finally, we extend a recent result by Vuorinen (2024) and show that all of the multiparameter bases have this property.
OFS et al. (Tue,) studied this question.