English

A Legendrian Turaev torsion via generating families

Symplectic Geometry 2020-10-21 v3

Abstract

We introduce a Legendrian invariant built out of the Turaev torsion of generating families. This invariant is defined for a certain class of Legendrian submanifolds of 1-jet spaces, which we call of Euler type. We use our invariant to study mesh Legendrians: a family of 2-dimensional Euler type Legendrian links whose linking pattern is determined by a bicolored trivalent ribbon graph. The Turaev torsion of mesh Legendrians is related to a certain monodromy of handle slides, which we compute in terms of the combinatorics of the graph. As an application, we exhibit pairs of Legendrian links in the 1-jet space of any orientable closed surface which are formally equivalent, cannot be distinguished by any natural Legendrian invariant, yet are not Legendrian isotopic. These examples appeared in a different guise in the work of the second author with J. Klein on pictures for K3K_3 and the higher Reidemeister torsion of circle bundles.

Keywords

Cite

@article{arxiv.1911.01393,
  title  = {A Legendrian Turaev torsion via generating families},
  author = {Daniel Alvarez-Gavela and Kiyoshi Igusa},
  journal= {arXiv preprint arXiv:1911.01393},
  year   = {2020}
}

Comments

54 pages, 26 figures