On local combinatorial formulas for Chern classes of triangulated circle bundle

Nikolai Mnev; Georgy Sharygin

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arXiv · 1608.04708

On local combinatorial formulas for Chern classes of triangulated circle bundle

Nikolai Mnev·Georgy Sharygin

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Abstract

Principal circle bundle over a PL polyhedron can be triangulated and thus obtains combinatorics. The triangulation is assembled from triangulated circle bundles over simplices. To every triangulated circle bundle over a simplex we associate a necklace (in combinatorial sense). We express rational local formulas for all powers of first Chern class in the terms of mathematical expectations of parities of the associated necklaces. This rational parity is a combinatorial isomorphism invariant of triangulated circle bundle over simplex, measuring mixing by triangulation of the circular graphs over vertices of the simplex. The goal of this note is to sketch the logic of deduction these formulas from Kontsevitch's cyclic invariant connection form on metric polygons.

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Nikolai Mnev, Georgy Sharygin. 2016-08-16. On local combinatorial formulas for Chern classes of triangulated circle bundle. https://arxiv.org/abs/1608.04708

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