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NORMALIZER OF THE CHEVALLEY GROUP OF TYPE E-7. / Vavilov, N. A.; Luzgarev, A. Yu.
In: St. Petersburg Mathematical Journal, Vol. 27, No. 6, 12.2016, p. 899-921.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - NORMALIZER OF THE CHEVALLEY GROUP OF TYPE E-7
AU - Vavilov, N. A.
AU - Luzgarev, A. Yu.
PY - 2016/12
Y1 - 2016/12
N2 - The simply connected Chevalley group G(E-7, R) of type E-7 is considered in the 56-dimensional representation. The main objective is to prove that the following four groups coincide: the normalizer of the elementary Chevalley group E(E-7, R), the normalizer of the Chevalley group G(E-7, R) itself, the transporter of E(E-7, R) into G(E-7, R), and the extended Chevalley group G (E-7, R). This holds over an arbitrary commutative ring R, with all normalizers and transporters being calculated in GL(56, R). Moreover, G (E-7, R) is characterized as the stabilizer of a system of quadrics. This last result is classically known over algebraically closed fields, here it is proved that the corresponding group scheme is smooth over Z, which implies that it holds over arbitrary commutative rings. These results are a key step in a subsequent paper, devoted to overgroups of exceptional groups in minimal representations.
AB - The simply connected Chevalley group G(E-7, R) of type E-7 is considered in the 56-dimensional representation. The main objective is to prove that the following four groups coincide: the normalizer of the elementary Chevalley group E(E-7, R), the normalizer of the Chevalley group G(E-7, R) itself, the transporter of E(E-7, R) into G(E-7, R), and the extended Chevalley group G (E-7, R). This holds over an arbitrary commutative ring R, with all normalizers and transporters being calculated in GL(56, R). Moreover, G (E-7, R) is characterized as the stabilizer of a system of quadrics. This last result is classically known over algebraically closed fields, here it is proved that the corresponding group scheme is smooth over Z, which implies that it holds over arbitrary commutative rings. These results are a key step in a subsequent paper, devoted to overgroups of exceptional groups in minimal representations.
KW - Chevalley groups
KW - elementary subgroups
KW - minimal modules
KW - invariant forms
KW - decomposition of unipotents
KW - root elements
KW - highest weight orbit
KW - REPRESENTATIONS
KW - OVERGROUPS
KW - группа Шевалле
KW - элементарная подгруппа
KW - инвариантные формы
KW - минимальные модули
KW - разложение унипотентов
KW - орбита вектора старшего веса
U2 - 10.1090/spmj/1426
DO - 10.1090/spmj/1426
M3 - Article
VL - 27
SP - 899
EP - 921
JO - St. Petersburg Mathematical Journal
JF - St. Petersburg Mathematical Journal
SN - 1061-0022
IS - 6
ER -
ID: 7599806