$K$-Bad Spheres

Martin Bendersky; Robert Thompson

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arXiv · 2601.02620

$K$-Bad Spheres

Martin Bendersky·Robert Thompson

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Abstract

In this paper we look at the $E$-completion of topological spaces where $E$ is a $p$-local ring spectrum. After a brief review of the concept of $E$-completion, we specialize to the case where $E=K$, $p$-local complex periodic $K$-theory, and consider the $K$-theory of the unstable sphere $S^{2n+1}$. We show that for certain values of $n$ and an odd prime $p$, the $K$-homology of the $K$-completion is not isomorphic to the $K$-homology of the sphere itself, thus in the terminology of Bousfield and Kan, these spheres are '$K$-bad'.

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BibTeX RIS

Martin Bendersky, Robert Thompson. 2026-01-06. $K$-Bad Spheres. https://arxiv.org/abs/2601.02620

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