$A_\infty$ condition for general bases revisited: Complete classification of definitions

Abstract:

We refer to the discussion on different characterizations of the $A_\infty$ class of weights, initiated by Duoandikoetxea, Martín-Reyes, and Ombrosi [Math. Z. 282 (2016), pp. 955–972]. Twelve definitions of the $A_\infty$ condition are considered. For cubes in $\mathbb {R}^d$ every two conditions are known to be equivalent, while for general bases we have a trichotomy: equivalence, one-way implication, or no dependency may occur. In most cases the relations between different conditions have already been established. Here all the unsolved cases are treated and, as a result, a full diagram of the said relations is presented.