Conformally flat circle bundles over surfaces
نویسندگان
چکیده
منابع مشابه
Conformally Flat Circle Bundles over Surfaces
We classify conformally flat Riemannian 3−manifolds which possesses a free isometric S−action.
متن کاملFlat circle bundles, pullbacks, and the circle made discrete
The fact that flat principal circle bundles are characterized by having zero real Euler classes has proved important in recent years in understanding whether total spaces of vector bundles over nonnegatively curved manifolds must support metrics with nonnegative curvature as well (see Theorem 6.3 and the discussion afterwards). Unfortunately, the proofs of this fact of which we are aware use ei...
متن کاملCircle bundles over 4-manifolds
Every 1-connected topological 4-manifold M admits a S1-covering by #r−1S 2 × S3, where r =rankH2(M ; Z). 2000 Mathematical Subject Classification: 57M50(55R25)
متن کاملAtoroidal surface bundles over surfaces
The main aim of this paper is to prove a finiteness result for atoroidal surface bundles over surfaces. It can be viewed from a number of different perspectives, and one can give several essentially equivalent statements. This, and related questions, have been considered by a number of authors. See [R] for a recent survey. First, we express it in group theoretical terms. By a surface group we m...
متن کاملMaximal Tori in the Contactomorphism Groups of Circle Bundles over Hirzebruch Surfaces
In a recent preprint Yael Karshon showed that there exist non-conjugate tori in a group of symplectomorphisms of a Hirzebruch surface. She counted them in terms of the cohomology class of the symplectic structure. We show that a similar phenomenon exists in the contactomorphism groups of pre-quantum circle bundles over Hirzebruch surfaces. Note that the contact structures in question are fillab...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Differential Geometry and its Applications
سال: 2015
ISSN: 0926-2245
DOI: 10.1016/j.difgeo.2015.02.004