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arXiv · 1804.05264

The slack realization space of a matroid

Madeline Brandt·Amy Wiebe
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Abstract

We introduce a new model for the realization space of a matroid, which is obtained from a variety defined by a saturated determinantal ideal, called the slack ideal, coming from the vertex-hyperplane incidence matrix of the matroid. This is inspired by a similar model for the slack realization space of a polytope. We show how to use these ideas to certify non-realizability of matroids, and describe an explicit relationship to the standard Grassmann-Pl\"ucker realization space model. We also exhibit a way of detecting projectively unique matroids via their slack ideals by introducing a toric ideal that can be associated to any matroid.

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Madeline Brandt, Amy Wiebe. 2018-04-14. The slack realization space of a matroid. https://arxiv.org/abs/1804.05264

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