The aim of the present paper is to study properties of Quasi conformally flat LP-Sasakian manifolds with a coefficient α. In this paper, we prove that a Quasi conformally flat LP-Sasakian manifold M (n > 3) with a constant coefficient α is an η−Einstein and in a quasi conformally flat LP-Sasakian manifold M (n > 3) with a constant coefficient α if the scalar curvature tensor is constant then M ...

TIn this article, the M-projective and Weyl curvature tensors on a normal paracontact metric manifold are discussed. For manifolds, pseudosymmetric cases investigated some interesting results obtained. We show that semisymmetric is of constant sectional curvature. also obtain an $\eta$-Einstein manifold. Finally, we support our topic with example.

Starting from a real analytic surface ℳ with conformal Cartan connection A. Bor´owka constructed minitwistor space of an asymptotically hyperbolic Einstein–Weyl manifold being the boundary. In this article, starting symmetry connection, we prove that symmetries on can be extended to obtained manifold.

For each composite number n 6= 2, there does not exist a single connected closed (n + 1)-manifold such that any smooth, simply-connected, closed nmanifold can be topologically flat embedded into it. There is a single connected closed 5-manifold W such that any simply-connected, 4-manifold M can be topologically flat embedded into W if M is either closed and indefinite, or compact and with non-e...

In this paper, we study the limiting behavior of the BrownYork mass and Hawking mass along nearly round surfaces at infinity of an asymptotically flat manifold. Nearly round surfaces can be defined in an intrinsic way. Our results show that the ADM mass of an asymptotically flat 3-manifold can be approximated by some geometric invariants of a family of nearly round surfaces which approach to in...

It is proved that for a non-Sasakian η-Einstein (κ, μ)-manifold M the following three conditions are equivalent: (a) M is flat and 3-dimensional, (b) M is Ricci-semisymmetric, and (c) M is ξ-Riccisemisymmetric. Then it is proved that an ξ-Ricci-semisymmetric (κ, μ)manifold M is either flat and 3-dimensional, or locally isometric to E × S(4), or an Einstein-Sasakian manifold. Mathematics Subject...

We investigate discrete groups G of isometries of a complete connected Riemannian manifold M which are generated by reflections, in particular those generated by disecting reflections. We show that these are Coxeter groups, and that the the orbit space M/G is isometric to a Weyl chamber C which is a Riemannian manifold with corners and certain angle conditions along intersections of faces. We c...

where G is a finite group and L is a faithful ZG-lattice of finite rank, i.e., a free Z-module of finite rank on which G acts faithfully. Let X be a flat manifold with fundamental group Γ. The group Aff(X) of affine self-equivalences of X is a Lie group. Its identity component Aff0(X) is a torus whose dimension is the rank of the center of Γ, and Aff(X)/Aff0(X) is isomorphic to Out(Γ), the oute...

Abstract. In this note we study constant mean curvature surfaces in asymptotically flat 3-manifolds. We prove that, outside a given compact subset in an asymptotically flat 3-manifold with positive mass, stable spheres of given constant mean curvature are unique. Therefore we are able to conclude that there is a unique foliation of stable spheres of constant mean curvature in an asymptotically ...

We classify flat strict nearly Kähler manifolds with (necessarily) indefinite metric. Any such manifold is locally the product of a flat pseudo-Kähler factor of maximal dimension and a strict flat nearly Kähler manifold of split signature (2m, 2m) with m ≥ 3. Moreover, the geometry of the second factor is encoded in a complex three-form ζ ∈ Λ3(Cm)∗. The first nontrivial example occurs in dimens...