On the slope of fibred threefolds

We study from a geographical point of wiew fibrations of threefolds over smooth curves $f: T \longrightarrow B$ such that the general fibre is of general type. We prove the non-negativity of certain relative invariants under general hypotheses and give lower bounds for $K^3_{T/B}$ depending on other...

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Detalles Bibliográficos
Autor: Barja Yáñez, Miguel Ángel|||0000-0003-2822-3938
Tipo de recurso: artículo
Fecha de publicación:1998
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/967
Acceso en línea:https://hdl.handle.net/2117/967
Access Level:acceso abierto
Palabra clave:Geometry, Algebraic
Surfaces
Fibred threefolds
slope
relative invariants
Fibrats (Matemàtica)
Superfícies
Varietats (Matemàtica)
Classificació AMS::14 Algebraic geometry::14D Families, fibrations
Classificació AMS::14 Algebraic geometry::14J Surfaces and higher-dimensional varieties
Descripción
Sumario:We study from a geographical point of wiew fibrations of threefolds over smooth curves $f: T \longrightarrow B$ such that the general fibre is of general type. We prove the non-negativity of certain relative invariants under general hypotheses and give lower bounds for $K^3_{T/B}$ depending on other relative invariants. We also study the influence of the relative irregularity $q(T)-g(B)$ on these bounds. A more detailed study of the lowest cases of the bounds is given.