The Classification of ...-symmetric Sasakian Manifolds.
The closed Friedman world model with the initial and final singularities as a non-commutative space
The most elegant definition of singularities in general relativity as b-boundary points, when applied to the closed Friedman world model, leads to the disastrous situation: both the initial and final singularities form the single point of the b-boundary which is not Hausdorff separated from the rest of space-time. We apply Alain Connes' method of non-commutative geometry, defined in terms of a C*-algebra, to this case. It turns out that both the initial and final singularities can be analysed as...
The Closed Geodesics of a Special Manifold.
The cohomology groups
The cohomology of with integer coefficients
The cohomology of the diffeomorphism group of a manifold is a Gelfand-Fuks cohomology
The collar theorem and examples.
The concept of cutting vectors for vector systems in the Euclidean plane.
The concept of invariant geometry of second order.
The cone over the Clifford torus in R4 ist ...-minimizing.
The conformal change of the metric of an almost Hermitian manifold applied to the antiholomorphic curvature tensor
By using the technique of decomposition of a Hermitian vector space under the action of a unitary group, Ganchev [2] obtained a tensor which he named the Weyl component of the antiholomorphic curvature tensor. We show that the same tensor can be obtained by direct application of the conformal change of the metric to the antiholomorphic curvature tensor. Also, we find some other conformally curvature tensors and examine some relations between them.
The conjugacy problem for relatively hyperbolic groups.
The construction of concomitants from an almost complex structure [Book]
The Construction of Negatively Ricci Curved Manifolds.
The Convergence of Zeta Functions for Certain Geodesic Flow Depends on Their Pressure.
The convex and concave decomposition of manifolds with real projective structures
The convex floating body.
The CR Yamabe conjecture the case
Let be a compact CR manifold of dimension with a contact form , and its associated CR conformal laplacien. The CR Yamabe conjecture states that there is a contact form on conformal to which has a constant Webster curvature. This problem is equivalent to the existence of a function such that , on . D. Jerison and J. M. Lee solved the CR Yamabe problem in the case where and is not locally CR equivalent to the sphere of . In a join work with R. Yacoub, the CR Yamabe problem...
The Critical Points Theory for the Closed Geodesics Problem.
The cubic representation of a submanifold.