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On the slope of fibred surfaces

Published online by Cambridge University Press:  22 January 2016

Miguel Ángel Barja
Affiliation:
Departament de Matmática Aplicada I, Universitat Politécnica de Catalunya, Diagonal 647, 08028 Barcelona, Spain, [email protected]
Francesco Zucconi
Affiliation:
Departament de Matmática Aplicada I, Universitat Politécnica de Catalunya, Diagonal 647, 08028 Barcelona, Spain, [email protected]
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Abstract

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We give an asymptotically sharp lower bound for the slope λ(f) of a fibration f : SB, where S is a surface and B is a curve, if there exists an involution on the general fibre F of f. We also construct a new lower bound of λ(f) depending increasingly on the irregularity of S; as an application of this new bound we have a criteria to control the existence of other fibrations on S.

Keywords

Type
Research Article
Copyright
Copyright © Editorial Board of Nagoya Mathematical Journal 2001

References

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