Frobenius morphisms and representations of algebras
| dc.creator | Deng, Bangming | |
| dc.creator | Du, Jie | |
| dc.date | 2003-07-18 | |
| dc.date.accessioned | 2026-07-07T04:59:45Z | |
| dc.date.available | 2026-07-07T04:59:45Z | |
| dc.description | By introducing Frobenius morphisms $F$ on algebras $A$ and their modules over the algebraic closure ${\bar \BF}_q$ of the finite field $\BF_q$ of $q$ elements, we establish a relation between the representation theory of $A$ over ${\bar \BF}_q$ and that of the $F$-fixed point algebra $A^F$ over $\BF_q$. More precisely, we prove that the category $\modh A^F$ of finite dimensional $A^F$-modules is equivalent to the subcategory of finite dimensional $F$-stable $A$-modules, and, when $A$ is finite dimensional, we establish a bijection between the isoclasses of indecomposable $A^F$-modules and the $F$-orbits of the isoclasses of indecomposable $A$-modules. Applying the theory to representations of quivers with automorphisms, we show that representations of a modulated quiver (or a species) over $\BF_q$ can be interpreted as $F$-stable representations of a corresponding quiver over ${\bar \BF}_q$. We further prove that every finite dimensional hereditary algebra over $\BF_q$ is Morita equivalent to some $A^F$, where $A$ is the path algebra of a quiver $Q$ over ${\bar \BF}_q$ and $F$ is induced from a certain automorphism of $Q$. A close relation between the Auslander-Reiten theories for $A$ and $A^F$ is established. In particular, we prove that the Auslander-Reiten (modulated) quiver of $A^F$ is obtained by "folding" the Auslander-Reiten quiver of $A$. Finally, by taking Frobenius fixed points, we are able to count the number of indecomposable representations of a modulated quiver with a given dimension vector and to establish part of Kac's theorem for all finite dimensional hereditary algebras over a finite field. | |
| dc.description | 28 pages | |
| dc.identifier | https://arxiv.org/abs/math/0307256 | |
| dc.identifier | http://arxiv.org/abs/math/0307256 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/68115 | |
| dc.subject | Rings and Algebras | |
| dc.subject | Representation Theory | |
| dc.subject | 16G20, 20G05 | |
| dc.title | Frobenius morphisms and representations of algebras | |
| dc.type | text |