Which weakly ramified group actions admit a universal formal deformation?
| dc.creator | Byszewski, Jakub | |
| dc.creator | Cornelissen, Gunther | |
| dc.date | 2007-08-24 | |
| dc.date | 2008-04-02 | |
| dc.date.accessioned | 2026-07-07T09:29:31Z | |
| dc.date.available | 2026-07-07T09:29:31Z | |
| dc.description | Consider a formal (mixed-characteristic) deformation functor D of a representation of a finite group G as automorphisms of a power series ring k[[t]] over a perfect field k of positive characteristic. Assume that the action of G is weakly ramified, i.e., the second ramification group is trivial. Examples of such representations are provided by a group action on an ordinary curve: the action of a ramification group on the completed local ring of any point on such a curve is weakly ramified. We prove that the only such D that are not pro-representable occur if k has characteristic two and G is of order two or isomorphic to a Klein group. Furthermore, we show that only the first of those has a non-pro-representable equicharacteristic deformation functor. | |
| dc.description | 16 pages; further minor corrections | |
| dc.identifier | https://arxiv.org/abs/0708.3279 | |
| dc.identifier | http://arxiv.org/abs/0708.3279 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/157815 | |
| dc.subject | Algebraic Geometry | |
| dc.subject | Number Theory | |
| dc.subject | 14B12 (Primary); 11G20, 14D15 (Secondary) | |
| dc.title | Which weakly ramified group actions admit a universal formal deformation? | |
| dc.type | text |