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arXiv · 2610.07631

A Finite-Geometric Obstruction and a Polytopal Separation of Buchstaber Invariants

Suyoung Choi·Hyeontae Jang
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Abstract

We construct a polytopal simplicial sphere that admits a mod 2 characteristic map but no mod 3 characteristic map, and hence no integral one. This shows that the Buchstaber number of a polytopal sphere can be strictly smaller than its real Buchstaber number, and gives a negative answer to the toric lifting problem.

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Suyoung Choi, Hyeontae Jang. 2026-10-06. A Finite-Geometric Obstruction and a Polytopal Separation of Buchstaber Invariants. https://arxiv.org/abs/2610.07631

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