Quasicircles and Bounded Turning Circles Modulo bi-Lipschitz Maps

Abstract

We construct a catalog, of snowflake type metric circles, that describes all metric quasicircles up to \bl\ equivalence. This is a metric space analog of a result due to Rohde. Our construction also works for all bounded turning metric circles; these need not be doubling. As a byproduct, we show that a metric quasicircle with Assouad dimension strictly less than two is bi-Lipschitz equivalent to a planar quasicircle.

30 pages, 3 figures, to appear in Rev. Mat. Iberoamericana