On chirality of toroidal embeddings of polyhedral graphs

Senja Barthel

doi:10.1142/s021821651750050x

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arXiv · 1505.06040

On chirality of toroidal embeddings of polyhedral graphs

Senja Barthel

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Abstract

We investigate properties of spatial graphs on the standard torus. It is known that nontrivial embeddings of planar graphs in the torus contain a nontrivial knot or a nonsplit link due to [1],[2]. Building on this and using the chirality of torus knots and links [3],[4], we prove that nontrivial embeddings of simple 3-connected planar graphs in the standard torus are chiral. For the case that the spatial graph contains a nontrivial knot, the statement was shown by Castle [5]. We give an alternative proof using minors instead of the Euler characteristic. To prove the case in which the graph embedding contains a nonsplit link, we show the chirality of Hopf ladders with at least three rungs, thus generalising a theorem of Simon [6].

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Senja Barthel. 2017-04-06. On chirality of toroidal embeddings of polyhedral graphs. https://doi.org/10.1142/s021821651750050x

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