Holomorphic maps onto varieties of nonnegative Kodaira dimension
Authors:
JunMuk Hwang, Stefan Kebekus and Thomas Peternell
Journal:
J. Algebraic Geom. 15 (2006), 551561
Published electronically:
April 21, 2005
MathSciNet review:
2219848
Fulltext PDF
Abstract 
References 
Additional Information
Abstract: A classical result in complex geometry says that the automorphism group of a manifold of general type is discrete. It is more generally true that there are only finitely many surjective morphisms between two fixed projective manifolds of general type. Rigidity of surjective morphisms, and the failure of a morphism to be rigid have been studied by a number of authors in the past. The main result of this paper states that surjective morphisms are always rigid, unless there is a clear geometric reason for it. More precisely, we can say the following. First, deformations of surjective morphisms between normal projective varieties are unobstructed unless the target variety is covered by rational curves. Second, if the target is not covered by rational curves, then surjective morphisms are infinitesimally rigid, unless the morphism factors via a variety with positivedimensional automorphism group. In this case, the Homscheme can be completely described.
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Additional Information
JunMuk Hwang
Affiliation:
Korea Institute for Advanced Study, 20743 Cheongnyangnidong, Seoul, 130722, Korea
Email:
jmhwang@kias.re.kr
Stefan Kebekus
Affiliation:
Mathematisches Institut, Universität zu Köln, Weyertal 8690, 50931 Köln, Germany
Email:
stefan.kebekus@math.unikoeln.de
Thomas Peternell
Affiliation:
Institut für Mathematik, Universität Bayreuth, 95440 Bayreuth, Germany
Email:
thomas.peternell@unibayreuth.de
DOI:
http://dx.doi.org/10.1090/S105639110500411X
PII:
S 10563911(05)00411X
Received by editor(s):
January 21, 2005
Received by editor(s) in revised form:
February 24, 2005
Published electronically:
April 21, 2005
Additional Notes:
JunMuk Hwang was supported by the Korea Research Foundation Grant (KRF2002070C00003). Stefan Kebekus was supported by a HeisenbergFellowship of the DFG. JunMuk Hwang, Stefan Kebekus and Thomas Peternell were supported in part by the program “Globale Methoden in der Komplexen Analysis” of the DFG
