Prescribed Projections and Efficient Coverings of Fractals in a Nonlinear Setting
Dr. Krystal Taylor (Dept. of Mathematics, Ohio State University)
03/18/2024 4:10pm
Abstract:
A classic theorem of Davies states that a set of positive Lebesgue measure can be
covered by lines in such a way that the union of the set of lines has the same measure
as the original set. This surprising and counter-intuitive result has a dual formulation
in the form of a prescribed projection theorem. We investigate an analogue of these
results in which lines are replaced by shifts of a fixed curve.
In particular, we show that a measurable set in the plane can be covered by translations
of a fixed open curve, obeying some mild curvature assumptions, in such a way that
the union of the translated curves has the same measure as the original set. Our results
rely on a Venetian blind construction and extend to transversal families of projections.
As an application, we consider how duality between curves and points can be used to
construct nonlinear Kakeya sets.