Planar self-similar set projections and fibres
Determine whether every line projection of a planar self-similar set with dense rotations and Hausdorff dimension $s>1$ has positive one-dimensional Lebesgue measure and fibres of Hausdorff dimension $s-1$ at Lebesgue-almost every point of the projected image.
References
Does every line projection of a planar self-similar set with dense rotations and dimension $s>1$ have positive length and fibres of dimension $s-1$ at Lebesgue-almost every point of its image?
— Absolute continuity and dimension conservation for self-similar sets and measures
(2609.29301 - Jin et al., 24 Sep 2026) in Section 7, “Prospects and open questions,” subsection “The planar set theorem”