arXiv subjects
Publications and source records attributed to Eve Shaw.
In this paper, we extend the result of arXiv:2409.13662 by showing that the set on which every pseudotangent is obtained on a Lipschitz curve can be any compact, uniformly disconnected set in Euclidean space which admits any Lipschitz capture. We do not obtain a characterization of such sets however, indeed we leave open the very strong question of whether or not a Lipschitz curve can obtain every pseudotangent at every point.
An important implication of Rademacher's Differentiation Theorem is that every Lipschitz curve $\Gamma$ infinitesimally looks like a line at almost all of its points in the sense that at $\mathcal{H}^1$-almost every point of $\Gamma$, the only tangent to $\Gamma$ is a straight line through the origin. In this article, we show that, in contrast, the infinitesimal structure of H\"older curves can be much more extreme. First we show that for every $s>1$ there exists a $(1/s)$-H\"older curve $\Gamma_s$ in a Euclidean space with $\mathcal{H}^s(\Gamma_s)>0$ such that $\mathcal{H}^s$-almost every point of $\Gamma_s$ admits infinitely many topologically distinct tangents. Second, we study the tangents of self-similar connected sets (which are canonical examples of H\"older curves) and prove that the curves $\Gamma_s$ have the additional property that $\mathcal{H}^s$-almost every point of $\Gamma_s$ admits infinitely many homeomorphically distinct tangents to $\Gamma_s$ which are not admitted as (not even bi-Lipschitz to) tangents to any self-similar set at typical points.
An infinite iterated function system (IIFS) is a countable collection of contraction maps on a compact metric space. In this paper we study the conditions under which the attractor of a such system admits a parameterization by a continuous or H\"older continuous map of the unit interval.