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arXiv · 2211.03104

The geometry of Coherent topoi and Ultrastructures

Ivan Di Liberti
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Abstract

We show that coherent topoi are right Kan injective with respect to flat embeddings of topoi. We recover the ultrastructure on their category of points as a consequence of this result. We speculate on possible notions of ultracategory in various arenas of formal model theory.

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Ivan Di Liberti. 2022-11-06. The geometry of Coherent topoi and Ultrastructures. https://arxiv.org/abs/2211.03104

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