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arXiv · 2604.26832

Primitive Two-Dimensional Words and Iterated Pedal Triangles via Symbolic Coding

Abstract

The notion of a two-dimensional word arises naturally in the study of combinatorics on words, while the iterative construction of pedal triangles results in a rich dynamical system in the study of geometry. At first, these two classes of objects seem to be unrelated. However, it is known that for all $n \geq 1$, the number of primitive two-dimensional words of dimension $2 \times n$ over a binary alphabet agrees with the number of triangles whose first similar pedal triangle is their $n$th pedal triangle. We construct a finite four-symbol coding of the sorted pedal map and use the resulting branch itineraries to give a bijection between these two classes.

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BibTeXRIS

Taylor J. Smith. 2026-04-29. Primitive Two-Dimensional Words and Iterated Pedal Triangles via Symbolic Coding. https://arxiv.org/abs/2604.26832

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