The relative Picard group of a comodule algebra and Harrison cohomology
| dc.creator | Caenepeel, S. | |
| dc.creator | Guedenon, T. | |
| dc.date | 2004-10-07 | |
| dc.date.accessioned | 2026-07-07T05:13:03Z | |
| dc.date.available | 2026-07-07T05:13:03Z | |
| dc.description | Let $A$ be a commutative comodule algebra over a commutative bialgebra $H$. The group of invertible relative Hopf modules maps to the Picard group of $A$, and the kernel is described as a quotient group of the group of invertible grouplike elements of the coring $A\ot H$, or as a Harrison cohomology group. Our methods are based on elementary $K$-theory. The Hilbert 90 Theorem follows as a corollary. The part of the Picard group of the coinvariants that becomes trivial after base extension embeds in the Harrison cohomology group, and the image is contained in a well-defined subgroup $E$. It equals $E$ if $H$ is a cosemisimple Hopf algebra over a field. | |
| dc.description | 12 pages | |
| dc.identifier | https://arxiv.org/abs/math/0410209 | |
| dc.identifier | http://arxiv.org/abs/math/0410209 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/72804 | |
| dc.subject | Rings and Algebras | |
| dc.subject | 16W30 | |
| dc.title | The relative Picard group of a comodule algebra and Harrison cohomology | |
| dc.type | text |