$A_{\infty }$ 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. 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.

10 pages, 1 table, 1 figure