Spectral networks and Fenchel-Nielsen coordinates

Lotte Hollands; Andrew Neitzke

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arXiv · 1312.2979

Spectral networks and Fenchel-Nielsen coordinates

Lotte Hollands·Andrew Neitzke

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Abstract

We explain that spectral networks are a unifying framework that incorporates both shear (Fock-Goncharov) and length-twist (Fenchel-Nielsen) coordinate systems on moduli spaces of flat SL(2,C) connections, in the following sense. Given a spectral network W on a punctured Riemann surface C, we explain the process of "abelianization" which relates flat SL(2)-connections (with an additional structure called "W-framing") to flat C*-connections on a covering. For any W, abelianization gives a construction of a local Darboux coordinate system on the moduli space of W-framed flat connections. There are two special types of spectral network, combinatorially dual to ideal triangulations and pants decompositions; these two types of network lead to Fock-Goncharov and Fenchel-Nielsen coordinates respectively.

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Lotte Hollands, Andrew Neitzke. 2013-12-10. Spectral networks and Fenchel-Nielsen coordinates. https://arxiv.org/abs/1312.2979

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