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arXiv · 1601.01409

On the spectrum of characters of ultrafilters

Shimon Garti·Menachem Magidor·Saharon Shelah
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Abstract

We show that the character spectrum $Sp_\chi(\lambda)$, for a singular cardinal $\lambda$ of countable cofinality, may include any prescribed set of regular cardinals between $\lambda$ and $2^\lambda$.

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Shimon Garti, Menachem Magidor, Saharon Shelah. 2016-01-07. On the spectrum of characters of ultrafilters. https://doi.org/10.1215/00294527-2018-0006

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