Tri-analytic Subvarieties of Hyperkähler Manifolds.
TT-tensors and conformally flat structures on 3-manifolds
We study TT-tensors on conformally flat 3-manifolds (M,g). The Cotton-York tensor linearized at g maps every symmetric tracefree tensor into one which is TT. The question as to whether this is the general solution to the TT-condition is viewed as a cohomological problem within an elliptic complex first found by Gasqui and Goldschmidt and reviewed in the present paper. The question is answered affirmatively when M is simply connected and has vanishing 2nd de Rham cohomology.
Tubes and the Geometry of the Kahler Manifolds
Tubular neighborhoods of totally geodesic hypersurfaces in hyperbolic mainfolds.
Twisted Product -submanifolds in a Locally Conformal Kaehler Manifold
Twisted spherical means in annular regions in and support theorems
Let be the class of all continuous functions on the annulus in with twisted spherical mean whenever and satisfy the condition that the sphere and ball In this paper, we give a characterization for functions in in terms of their spherical harmonic coefficients. We also prove support theorems for the twisted spherical means in which improve some of the earlier results.
Twisteurs des orbites coadjointes et métriques hyper-pseudokählériennes
Twisteurs et applications harmoniques en dimension 4
Twistor fibrations giving primitive harmonic maps of finite type.
Twistor forms on Kähler manifolds
Twistor forms are a natural generalization of conformal vector fields on riemannian manifolds. They are defined as sections in the kernel of a conformally invariant first order differential operator. We study twistor forms on compact Kähler manifolds and give a complete description up to special forms in the middle dimension. In particular, we show that they are closely related to hamiltonian 2-forms. This provides the first examples of compact Kähler manifolds with non–parallel twistor forms in...
Twistor Holomorphic Immersions of Real Surfaces Into Kähler Surface.
Twistor spaces for Riemannian symmetric spaces.
Twistor spaces over the connected sum of 3 projective planes
Twistor transforms of quaternionic functions and orthogonal complex structures
The theory of slice-regular functions of a quaternion variable is applied to the study of orthogonal complex structures on domains of . When is a symmetric slice domain, the twistor transform of such a function is a holomorphic curve in the Klein quadric. The case in which is the complement of a parabola is studied in detail and described by a rational quartic surface in the twistor space .
Twistors and gauge fields.
Two applications of an integral formula
Two generalizations of Cheeger-Gromoll splitting theorem via Bakry-Emery Ricci curvature
In this paper, we prove two generalized versions of the Cheeger-Gromoll splitting theorem via the non-negativity of the Bakry-Émery Ricci curavture on complete Riemannian manifolds.
Two new estimates for eigenvalues of Dirac operators
We establish lower and upper eigenvalue estimates for Dirac operators in different settings, a new Kirchberg type estimate for the first eigenvalue of the Dirac operator on a compact Kähler spin manifold in terms of the energy momentum tensor, and an upper bound for the smallest eigenvalues of the twisted Dirac operator on Legendrian submanifolds of Sasakian manifolds. The sharpness of those estimates is also discussed.
Two special simply connected spaces of nonpositive curvature.
Two supergeometries from fourfold gradings of superalgebras