A reduced planar body with area greater than $πΔ^2/4$
Metric Geometry
2026-06-26 v1 Computational Geometry
Combinatorics
Abstract
We construct a reduced planar convex body with thickness and Thus is a counterexample to Lassak's conjectured upper bound for planar reduced bodies. The construction is given by an explicit support function, and the proofs use only elementary support-function, width, area, and contact-point computations.
Cite
@article{arxiv.2606.28612,
title = {A reduced planar body with area greater than $πΔ^2/4$},
author = {Scott Duke Kominers},
journal= {arXiv preprint arXiv:2606.28612},
year = {2026}
}
Comments
10 pages, 2 figures, plus verification source code