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Universally extendible characters
Abstract
Let theta be an ordinary character or a Brauer character of a finite group N. We show that theta extends to every overgroup G=Gθtrianglerighteq N if and only if Z(N) <= Ker(theta) and the deflated character of Inn(N) extends to Aut(N)_theta. This equivalence is compatible with fields of values. A similar investigation for extensions from subnormal subgroups leads to a new characteristic subgroup of N.
Related
BibTeX
@misc{sambale2026universally,
title = {{Universally extendible characters}},
author = {Benjamin Sambale},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.20520},
eprint = {2610.20520},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.20520},
}
RIS
TY - UNPB
TI - Universally extendible characters
AU - Benjamin Sambale
PY - 2026
DA - 2026/10/14
PB - arXiv
DO - 10.48550/arxiv.2610.20520
UR - https://arxiv.org/abs/2610.20520
AB - Let theta be an ordinary character or a Brauer character of a finite group N. We show that theta extends to every overgroup G=G_θtrianglerighteq N if and only if Z(N) <= Ker(theta) and the deflated character of Inn(N) extends to Aut(N)_theta. This equivalence is compatible with fields of values. A similar investigation for extensions from subnormal subgroups leads to a new characteristic subgroup of N.
ER -