In studying temperature fluctuations in the cosmic microwave background Weinberg has noted that some ease of calculation and insight can be achieved by looking at structure perturbed light cone on which photons propagate. his approach worked a specific gauge specialized to around standard Robertson-Walker cosmological model with vanishing spatial three-curvature. this paper we generalize analys...

In this paper we study a Riemanian metric on the tangent bundle T (M) of a Riemannian manifold M which generalizes Sasaki metric and Cheeger Gromoll metric and a compatible almost complex structure which together with the metric confers to T (M) a structure of locally conformal almost Kählerian manifold. This is the natural generalization of the well known almost Kählerian structure on T (M). W...

In this paper, we study conformal submersions from Ricci solitons to Riemannian manifolds with non-trivial examples. First, some properties of the O’Neill tensor A in case submersion. We also find a necessary and sufficient condition for submersion be totally geodesic calculate total manifold such map different assumptions. Further, consider $$F:M \rightarrow N$$ soliton obtain conditions fiber...

Let (M,g) be a compact Riemannian manifold. The conformal class of g consists of all metrics g̃ = e2ug for any smooth function u. A central theme in conformal geometry is the study of properties that are common to all metrics in the same conformal class, and the understanding and classification of all the conformal classes. For this purpose it is often useful to be able to single out a unique re...

In this note we study the conformal metrics of constant Q curvature on closed locally conformally flat manifolds. We prove that for a closed locally conformally flat manifold of dimension n ≥ 5 and with Poincarë exponent less than n−4 2 , the set of conformal metrics of positive constant Q and positive scalar curvature is compact in the C∞ topology.

We apply the Bogomol’nyi technique, which is usually invoked in the study of solitons or models with topological invariants, to the case of elastic energy of vesicles. We show that spontaneous bending contribution caused by any deformation from metastable bending shapes falls in two distinct topological sets: shapes of spherical topology and shapes of non-spherical topology experience respectiv...

We study logarithmic conformal field theories (LCFTs) through the introduction of nilpotent conformal weights. Using this device, we derive the properties of LCFT’s such as the transformation laws, singular vectors and the structure of correlation functions. We discuss the emergence of an extra energy momentum tensor, which is the logarithmic partner of the energy momentum tensor. PACS: 11.25.Hf

Abstract In this article, we investigate perfect fluid spacetimes equipped with concircular vector field. At first, in a spacetime admitting field, prove that the velocity field annihilates conformal curvature tensor. addition, dimension 4, show is generalized Robertson–Walker Einstein fibre. It proved if furnished admits second order symmetric parallel tensor P , then either equation of state ...

In this paper we prove that under a lower bound on the Ricci curvature and an asymptotic assumption on the scalar curvature, a complete conformally compact manifold (M, g), with a pole p and with the conformal infinity in the conformal class of the round sphere, has to be the hyperbolic space.

An approximation theorem for minimal surfaces by complete minimal surfaces of finite total curvature in R is obtained. This result can be extended to the family of complete minimal surfaces of weak finite total curvature, that is to say, having finite total curvature on proper regions of finite conformal type. We deal only with the orientable case. As a consequence, complete minimal surfaces in...