Dynamics on the SU(2,1)-character variety of the one-holed torus

Sean Lawton; Sara Maloni; Frédéric Palesi

doi:10.1112/mod.2025.3

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arXiv · 2402.10838

Dynamics on the SU(2,1)-character variety of the one-holed torus

Sean Lawton·Sara Maloni·Frédéric Palesi

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Abstract

We study the relative SU(2,1)-character varieties of the one-holed torus, and the action of the mapping class group on them. We use an explicit description of the character variety of the free group of rank two in SU(2,1) in terms of traces, which allow us to describe the topology of the character variety. We then combine this description with a generalization of the Farey graph adapted to this new combinatorial setting, using ideas introduced by Bowditch. Using these tools, we can describe an open domain of discontinuity for the action of the mapping class group which strictly contains the set of convex cocompact characters, and we give several characterizations of representations in this domain.

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Sean Lawton, Sara Maloni, Frédéric Palesi. 2024-02-16. Dynamics on the SU(2,1)-character variety of the one-holed torus. https://doi.org/10.1112/mod.2025.3

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