scholarly journals Branched coverings of the 2-sphere

Author(s):  
Arcelino Bruno Lobato do Nascimento
Keyword(s):  
Author(s):  
Christine Breiner ◽  
Chikako Mese

Abstract Let S be a surface with a metric d satisfying an upper curvature bound in the sense of Alexandrov (i.e. via triangle comparison). We show that an almost conformal harmonic map from a surface into ( S , d ) {(S,d)} is a branched covering. As a consequence, if ( S , d ) {(S,d)} is homeomorphically equivalent to the 2-sphere 𝕊 2 {\mathbb{S}^{2}} , then it is conformally equivalent to 𝕊 2 {\mathbb{S}^{2}} .


2003 ◽  
Vol 10 (1) ◽  
pp. 37-43
Author(s):  
E. Ballico

Abstract We consider the vanishing problem for higher cohomology groups on certain infinite-dimensional complex spaces: good branched coverings of suitable projective spaces and subvarieties with a finite free resolution in a projective space P(V ) (e.g. complete intersections or cones over finitedimensional projective spaces). In the former case we obtain the vanishing result for H 1. In the latter case the corresponding results are only conditional for sheaf cohomology because we do not have the corresponding vanishing theorem for P(V ).


1999 ◽  
Vol 12 (2) ◽  
Author(s):  
Beatrice Ruini ◽  
Fulvia Spaggiari ◽  
Alberto Cavicchioli
Keyword(s):  

2011 ◽  
Vol 54 (1) ◽  
pp. 33-45 ◽  
Author(s):  
Alberto Cavicchioli ◽  
Fulvia Spaggiari ◽  
Agnese Ilaria Telloni

AbstractWe consider orientable closed connected 3-manifolds obtained by performing Dehn surgery on the components of some classical links such as Borromean rings and twisted Whitehead links. We find geometric presentations of their fundamental groups and describe many of them as 2-fold branched coverings of the 3-sphere. Finally, we obtain some topological applications on the manifolds given by exceptional surgeries on hyperbolic 2-bridge knots.


2008 ◽  
Vol 155 (16) ◽  
pp. 1820-1839
Author(s):  
Bronislaw Wajnryb ◽  
Agnieszka Wisniowska-Wajnryb
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1971 ◽  
Vol 18 (2) ◽  
pp. 103-114 ◽  
Author(s):  
William L. Reddy
Keyword(s):  

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