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arXiv · 2107.13499

Boundary slopes for the Markov ordering on relatively prime pairs

Jonah Gaster
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Abstract

Following McShane, we employ the stable norm on the homology of the modular torus to investigate the Markov ordering on the set of relatively prime integer pairs $(q,p)$ with $q\ge p\ge0$. Our main theorem is a characterization of slopes along which the Markov ordering is monotone with respect to $q$, confirming conjectures of Lee-Li-Rabideau-Schiffler that refine conjectures of Aigner. The main tool is an explicit computation of the slopes at the corners of the stable norm ball for the modular torus.

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Jonah Gaster. 2021-07-28. Boundary slopes for the Markov ordering on relatively prime pairs. https://arxiv.org/abs/2107.13499

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