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.

Cite this paper

@article{smith2023,
  title = {A chiral aperiodic monotile},
  author = {David Smith and Joseph Samuel Myers and Craig S. Kaplan and Chaim Goodman-Strauss},
  journal = {Combinatorial Theory, 4(2) (2024)},
  year = {2023},
  month = {May},
  doi = {10.5070/c64264241},
  url = {https://doi.org/10.5070/c64264241},
}