ON THE BEHAVIOR OF JORDAN-ALGEBRA NORMS ON ASSOCIATIVE ALGEBRAS

Citation
Mc. Garcia et al., ON THE BEHAVIOR OF JORDAN-ALGEBRA NORMS ON ASSOCIATIVE ALGEBRAS, Studia Mathematica, 113(1), 1995, pp. 81-100
Citations number
27
Categorie Soggetti
Mathematics, General",Mathematics
Journal title
ISSN journal
00393223
Volume
113
Issue
1
Year of publication
1995
Pages
81 - 100
Database
ISI
SICI code
0039-3223(1995)113:1<81:OTBOJN>2.0.ZU;2-6
Abstract
We prove that for a suitable associative (real or complex) algebra whi ch has many nice algebraic properties, such as being simple and having minimal idempotents, a norm can be given such that the mapping (a,b) bar arrow pointing right ab + ba is jointly continuous while (a, b) ba r arrow pointing right ab is only separately continuous. We also prove that such a pathology cannot arise for associative simple algebras wi th a unit. Similar results are obtained for the so-called ''norm exten sion problem'', and the relationship between these results and the nor med versions of Zel'manov's prime theorem for Jordan algebras are disc ussed.