On the Bicanonical Morphism of quadruple Galois canonical covers
I In this article we study the bicanonical map ϕ2 of quadruple Galois canonical covers X of surfaces of minimal degree. We show that ϕ2 has diverse behavior and exhibits most of the complexities that are possible for a bicanonical map of surfaces of general type, depending on the type of X. There ar...
| Autores: | , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2011 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/41932 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/41932 |
| Access Level: | acceso abierto |
| Palabra clave: | 512.7 Surfaces of general type Bicanonical map Quadruple Galois canonical covers Canonical ring Surfaces of minimal degree Geometria algebraica 1201.01 Geometría Algebraica |
| Sumario: | I In this article we study the bicanonical map ϕ2 of quadruple Galois canonical covers X of surfaces of minimal degree. We show that ϕ2 has diverse behavior and exhibits most of the complexities that are possible for a bicanonical map of surfaces of general type, depending on the type of X. There are cases in which ϕ2 is an embedding, and if it so happens, ϕ2 embeds X as a projectively normal variety, and there are cases in which ϕ2 is not an embedding. If the latter, ϕ2 is finite of degree 1, 2 or 4. We also study the canonical ring of X, proving that it is generated in degree less than or equal to 3 and finding the number of generators in each degree. For generators of degree 2 we find a nice general formula which holds for canonical covers of arbitrary degrees. We show that this formula depends only on the geometric and the arithmetic genus of X. |
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