The Galois extensions induced by idempotents in a Galois algebra

Let B be a Galois algebra with Galois group G, Jg={b∈B|bx=g(x)b   for all   x∈B} for each g∈G, eg the central idempotent such that BJg=Beg, and eK=∑g∈K,eg≠1eg for a subgroup K of G. Then BeK is a Galois extension with the Galois group G(eK)(={g∈G|g(eK)=eK}) containing K and the normalizer N(K) of K...

Full description

Saved in:
Bibliographic Details
Main Authors: George Szeto, Lianyong Xue
Format: Article
Language:English
Published: Wiley 2002-01-01
Series:International Journal of Mathematics and Mathematical Sciences
Online Access:http://dx.doi.org/10.1155/S0161171202007767
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832550146405040128
author George Szeto
Lianyong Xue
author_facet George Szeto
Lianyong Xue
author_sort George Szeto
collection DOAJ
description Let B be a Galois algebra with Galois group G, Jg={b∈B|bx=g(x)b   for all   x∈B} for each g∈G, eg the central idempotent such that BJg=Beg, and eK=∑g∈K,eg≠1eg for a subgroup K of G. Then BeK is a Galois extension with the Galois group G(eK)(={g∈G|g(eK)=eK}) containing K and the normalizer N(K) of K in G. An equivalence condition is also given for G(eK)=N(K), and BeG is shown to be a direct sum of all Bei generated by a minimal idempotent ei. Moreover, a characterization for a Galois extension B is shown in terms of the Galois extension BeG and B(1−eG).
format Article
id doaj-art-73eb842cf4f841e196d86fc421fd95b4
institution Kabale University
issn 0161-1712
1687-0425
language English
publishDate 2002-01-01
publisher Wiley
record_format Article
series International Journal of Mathematics and Mathematical Sciences
spelling doaj-art-73eb842cf4f841e196d86fc421fd95b42025-02-03T06:07:35ZengWileyInternational Journal of Mathematics and Mathematical Sciences0161-17121687-04252002-01-0129737538010.1155/S0161171202007767The Galois extensions induced by idempotents in a Galois algebraGeorge Szeto0Lianyong Xue1Department of Mathematics, Bradley University, Peoria 61625, IL, USADepartment of Mathematics, Bradley University, Peoria 61625, IL, USALet B be a Galois algebra with Galois group G, Jg={b∈B|bx=g(x)b   for all   x∈B} for each g∈G, eg the central idempotent such that BJg=Beg, and eK=∑g∈K,eg≠1eg for a subgroup K of G. Then BeK is a Galois extension with the Galois group G(eK)(={g∈G|g(eK)=eK}) containing K and the normalizer N(K) of K in G. An equivalence condition is also given for G(eK)=N(K), and BeG is shown to be a direct sum of all Bei generated by a minimal idempotent ei. Moreover, a characterization for a Galois extension B is shown in terms of the Galois extension BeG and B(1−eG).http://dx.doi.org/10.1155/S0161171202007767
spellingShingle George Szeto
Lianyong Xue
The Galois extensions induced by idempotents in a Galois algebra
International Journal of Mathematics and Mathematical Sciences
title The Galois extensions induced by idempotents in a Galois algebra
title_full The Galois extensions induced by idempotents in a Galois algebra
title_fullStr The Galois extensions induced by idempotents in a Galois algebra
title_full_unstemmed The Galois extensions induced by idempotents in a Galois algebra
title_short The Galois extensions induced by idempotents in a Galois algebra
title_sort galois extensions induced by idempotents in a galois algebra
url http://dx.doi.org/10.1155/S0161171202007767
work_keys_str_mv AT georgeszeto thegaloisextensionsinducedbyidempotentsinagaloisalgebra
AT lianyongxue thegaloisextensionsinducedbyidempotentsinagaloisalgebra
AT georgeszeto galoisextensionsinducedbyidempotentsinagaloisalgebra
AT lianyongxue galoisextensionsinducedbyidempotentsinagaloisalgebra