Algebraic & Geometric Topology

Satellites of Legendrian knots and representations of the Chekanov–Eliashberg algebra

Lenhard Ng and Daniel Rutherford

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We develop a close relation between satellites of Legendrian knots in 3 and the Chekanov–Eliashberg differential graded algebra of the knot. In particular, we generalize the well-known correspondence between rulings of a Legendrian knot in 3 and augmentations of its DGA by showing that the DGA has finite-dimensional representations if and only if there exist certain rulings of satellites of the knot. We derive several consequences of this result, notably that the question of existence of ungraded finite-dimensional representations for the DGA of a Legendrian knot depends only on the topological type and Thurston–Bennequin number of the knot.

Article information

Algebr. Geom. Topol., Volume 13, Number 5 (2013), 3047-3097.

Received: 15 June 2012
Revised: 8 April 2013
Accepted: 8 April 2013
First available in Project Euclid: 19 December 2017

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Mathematical Reviews number (MathSciNet)

Zentralblatt MATH identifier

Primary: 57R17: Symplectic and contact topology
Secondary: 53D42: Symplectic field theory; contact homology 57M25: Knots and links in $S^3$ {For higher dimensions, see 57Q45}

Legendrian knot Legendrian contact homology normal ruling satellite


Ng, Lenhard; Rutherford, Daniel. Satellites of Legendrian knots and representations of the Chekanov–Eliashberg algebra. Algebr. Geom. Topol. 13 (2013), no. 5, 3047--3097. doi:10.2140/agt.2013.13.3047.

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