Classification of smooth congruences of low degree

We give a complete classification of smooth congruences - i.e. surfaces in the Grassmann variety of lines in P 3C identified with a smooth quadric in P5- of degree at most 8, by studying which surfaces of P5can lie in a smooth quadric and proving their existence. We present their ideal sheaf as a qu...

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Detalles Bibliográficos
Autores: Arrondo Esteban, Enrique, Sols Lucía, Ignacio
Tipo de recurso: artículo
Fecha de publicación:1989
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/57185
Acceso en línea:https://hdl.handle.net/20.500.14352/57185
Access Level:acceso abierto
Palabra clave:512.7
Smooth congruences
surfaces in the Grassmann variety of lines
cohomology
postulation
linear normality
Hilbert scheme
Geometria algebraica
1201.01 Geometría Algebraica
Descripción
Sumario:We give a complete classification of smooth congruences - i.e. surfaces in the Grassmann variety of lines in P 3C identified with a smooth quadric in P5- of degree at most 8, by studying which surfaces of P5can lie in a smooth quadric and proving their existence. We present their ideal sheaf as a quotient of natural bundles in the Grassmannian, what provides a perfect knowledge of its cohomology (for example postulation or linear normality), as well as many information on the Hilbert scheme of these families, such as dimension, smoothness, unirationality - and thus irreducibility - and in some cases rationality.