PreprintCC BY 4.0arXiv
Finite groups with a unique real $2$-block
Abstract
Let p be a prime, and let B be a p-block of a finite group G. A p-block B is called \emph{real} if the set of irreducible ordinary characters contained in B is invariant under complex conjugation. Motivated by Harris' classification of the finite groups with a unique p-block for an arbitrary prime p, and by McHugh and Schaeffer Fry's classification of the finite quasi-simple groups with a unique real $2$-block, we classify, in this paper, all finite groups admitting exactly one real $2$-block.
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BibTeX
@misc{zeng2026finite,
title = {{Finite groups with a unique real $2$-block}},
author = {Yu Zeng and Fuming Jiang},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.20203},
eprint = {2609.20203},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.20203},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Finite groups with a unique real $2$-block
AU - Yu Zeng
AU - Fuming Jiang
PY - 2026
DA - 2026/09/24
PB - arXiv
DO - 10.48550/arxiv.2609.20203
UR - https://arxiv.org/abs/2609.20203
AB - Let p be a prime, and let B be a p-block of a finite group G. A p-block B is called \emph{real} if the set of irreducible ordinary characters contained in B is invariant under complex conjugation. Motivated by Harris' classification of the finite groups with a unique p-block for an arbitrary prime p, and by McHugh and Schaeffer Fry's classification of the finite quasi-simple groups with a unique real $2$-block, we classify, in this paper, all finite groups admitting exactly one real $2$-block.
ER -