Coalgebra extensions and algebra coextensions of Galois type

Authors
Brzezinski, T Hajac, PM
Citation
T. Brzezinski et Pm. Hajac, Coalgebra extensions and algebra coextensions of Galois type, COMM ALGEB, 27(3), 1999, pp. 1347-1367
Citations number
23
Categorie Soggetti
Mathematics
Journal title
COMMUNICATIONS IN ALGEBRA
ISSN journal
00927872 → ACNP
Volume
27
Issue
3
Year of publication
1999
Pages
1347 - 1367
Database
ISI
SICI code
0092-7872(1999)27:3<1347:CEAACO>2.0.ZU;2-3
Abstract
The notion of a coalgebra-Galois extension is defined as a natural generali sation of a Hopf-Galois extension. It is shown that any coalgebra-Galois ex tension induces a unique entwining map psi compatible with the right coacti on. For the dual notion of an algebra-Galois coextension it is also proven that there always exists a unique entwining structure compatible with the r ight action.