English

A chiral aperiodic monotile

Combinatorics 2024-10-01 v2 Discrete Mathematics Metric Geometry

Abstract

The recently discovered "hat" aperiodic monotile mixes unreflected and reflected tiles in every tiling it admits, leaving open the question of whether a single shape can tile aperiodically using translations and rotations alone. We show that a close relative of the hat -- the equilateral member of the continuum to which it belongs -- is a weakly chiral aperiodic monotile: it admits only non-periodic tilings if we forbid reflections by fiat. Furthermore, by modifying this polygon's edges we obtain a family of shapes called Spectres that are strictly chiral aperiodic monotiles: they admit only chiral non-periodic tilings based on a hierarchical substitution system.

Keywords

Cite

@article{arxiv.2305.17743,
  title  = {A chiral aperiodic monotile},
  author = {David Smith and Joseph Samuel Myers and Craig S. Kaplan and Chaim Goodman-Strauss},
  journal= {arXiv preprint arXiv:2305.17743},
  year   = {2024}
}

Comments

25 pages, 12 figures. Copyedited journal version of article

R2 v1 2026-06-28T10:48:43.890Z