Birational Rowmotion and the Octahedron Recurrence

Joseph Johnson; Ricky Ini Liu

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arXiv · 2204.04255

Birational Rowmotion and the Octahedron Recurrence

Joseph Johnson·Ricky Ini Liu

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Abstract

We use the octahedron recurrence to give a simplified statement and proof of a formula for iterated birational rowmotion on a product of two chains, first described by Musiker and Roby. Using this, we show that weights of certain chains in rectangles shift in a predictable way under the action of rowmotion. We then define generalized Stanley-Thomas words whose cyclic rotation uniquely determines birational rowmotion on the product of two chains. We also discuss the relationship between rowmotion and birational RSK and give a birational analogue of Greene's theorem in this setting.

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Joseph Johnson, Ricky Ini Liu. 2022-04-08. Birational Rowmotion and the Octahedron Recurrence. https://arxiv.org/abs/2204.04255

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