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arXiv · 2512.08081

Shelah Ultrafilters

Emmanuel Balderas·David Chodounský·Osvaldo Guzmán
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Abstract

In this paper, we study a special type of ultrafilter which we call Shelah ultrafilter. We show that it is possible to add a Shelah ultrafilter using a special forcing notion. We also show that Shelah ultrafilters turn out to be I-ultrafilters for many Borel ideals.

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Emmanuel Balderas, David Chodounský, Osvaldo Guzmán. 2025-12-08. Shelah Ultrafilters. https://arxiv.org/abs/2512.08081

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