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Bibliographic Details
Main Author: Baker, Andrew
Format: Preprint
Published: 2023
Subjects:
Online Access:https://arxiv.org/abs/2309.05921
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author Baker, Andrew
author_facet Baker, Andrew
contents The algebraic Joker module was originally described in the 1970s by Adams and Priddy and is a $5$-dimensional module over the subHopf algebra $\mathcal{A}(1)$ of the mod $2$ Steenrod algebra. It is a self-dual endotrivial module, i.e., an invertible object in the stable module category of $\mathcal{A}(1)$. Recently it has been shown that no analogues exist for $\mathcal{A}(n)$ with $n>1$. Using iterated doubling this also gives an iterated double which is an $\mathcal{A}(n)$-module but not stably invertible. In previous work the author showed that for $n=1,2,3$ these iterated doubles were realisable as cohomology of CW spectra, but no such realisation existed for $n>3$. The main point of the paper is to show that in the height $2$ chromatic context, the Morava $K$-theory of double Jokers realise an exceptional endotrivial module over the quaternion group of order $8$ that only exists over a field of characteristic $2$ containing a primitive cube root of unity. This has connections with certain Massey products in the cohomology of the quaternion group.
format Preprint
id arxiv_https___arxiv_org_abs_2309_05921
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Endotrivial modules for the quaternion group and iterated Jokers in chromatic homotopy theory
Baker, Andrew
Algebraic Topology
55S25 (Primary 5) 55N34, 20C20 (Secondary)
The algebraic Joker module was originally described in the 1970s by Adams and Priddy and is a $5$-dimensional module over the subHopf algebra $\mathcal{A}(1)$ of the mod $2$ Steenrod algebra. It is a self-dual endotrivial module, i.e., an invertible object in the stable module category of $\mathcal{A}(1)$. Recently it has been shown that no analogues exist for $\mathcal{A}(n)$ with $n>1$. Using iterated doubling this also gives an iterated double which is an $\mathcal{A}(n)$-module but not stably invertible. In previous work the author showed that for $n=1,2,3$ these iterated doubles were realisable as cohomology of CW spectra, but no such realisation existed for $n>3$. The main point of the paper is to show that in the height $2$ chromatic context, the Morava $K$-theory of double Jokers realise an exceptional endotrivial module over the quaternion group of order $8$ that only exists over a field of characteristic $2$ containing a primitive cube root of unity. This has connections with certain Massey products in the cohomology of the quaternion group.
title Endotrivial modules for the quaternion group and iterated Jokers in chromatic homotopy theory
topic Algebraic Topology
55S25 (Primary 5) 55N34, 20C20 (Secondary)
url https://arxiv.org/abs/2309.05921