Global geometry of surfaces defined by non-positive and negative at infinity valuations

We consider plane divisorial valuations of Hirzebruch surfaces and introduce the concepts of non-positivity and negativity at infinity. We prove that the surfaces given by valuations of the last types have nice global and local geometric properties. Moreover, non-positive at infinity divisorial valu...

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Detalles Bibliográficos
Autor: Moreno Ávila, Carlos Jesús
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/672247
Acceso en línea:http://hdl.handle.net/10803/672247
http://dx.doi.org/10.6035/14104.2021.725853
Access Level:acceso abierto
Palabra clave:Non-positive at infinity valuations
Rational surfaces
Cone of curves
Newton-Okounkov bodies
Plane valuations
Singularities
Ciències naturals, químiques, físiques i matemàtiques
514
Descripción
Sumario:We consider plane divisorial valuations of Hirzebruch surfaces and introduce the concepts of non-positivity and negativity at infinity. We prove that the surfaces given by valuations of the last types have nice global and local geometric properties. Moreover, non-positive at infinity divisorial valuations are those divisorial valuations of Hirzebruch surfaces providing rational surfaces with minimal generated cone of curves. Non-positivity and negativity at infinity are also extended to the class of real valuations of the projective plane and the Hirzebruch surfaces. Finally, we compute the Seshadri-type constants for pairs formed by a big divisor and a divisorial valuation of a Hirzebruch surface and obtain the vertices of the Newton-Okounkov bodies of pairs as above under the non-positivity at infinity property.