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Finiteness properties of profinite blocks and blocks with defect group ℤpn
Abstract
We prove that any block of a profinite group with a topologically finitely generated defect group D is isomorphic to a block of a virtually pro-p group, and if D is finitely presented then so is the basic algebra of the block over k. Using these general results we then prove that any block with defect group D=ℤpn is Morita equivalent to 𝒪α[[ℤpnrtimes E]] for a finite p'-group E acting faithfully and a $2$-cocycle α∈ H2(E,k×). In particular, Donovan's conjecture holds for such blocks of profinite groups.
Related
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- Finiteness properties of closed subgroups of Thompson's group F
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- Homological finiteness properties of wreath products
BibTeX
@misc{eisele2026finiteness,
title = {{Finiteness properties of profinite blocks and blocks with defect group $\mathbb Z_p^n$}},
author = {Florian Eisele and John W. MacQuarrie},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.32587},
eprint = {2609.32587},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.32587},
}
RIS
TY - UNPB
TI - Finiteness properties of profinite blocks and blocks with defect group ℤ_p^n
AU - Florian Eisele
AU - John W. MacQuarrie
PY - 2026
DA - 2026/09/26
PB - arXiv
DO - 10.48550/arxiv.2609.32587
UR - https://arxiv.org/abs/2609.32587
AB - We prove that any block of a profinite group with a topologically finitely generated defect group D is isomorphic to a block of a virtually pro-p group, and if D is finitely presented then so is the basic algebra of the block over k. Using these general results we then prove that any block with defect group D=ℤ_p^n is Morita equivalent to 𝒪_α[[ℤ_p^nrtimes E]] for a finite p'-group E acting faithfully and a $2$-cocycle α∈ H^2(E,k^×). In particular, Donovan's conjecture holds for such blocks of profinite groups.
ER -