Results 21 to 30 of about 2,034,699 (144)
Topology of the ambient boundary and the convergence of causal curves [PDF]
, 2015 We discuss the topological nature of the boundary spacetime, the conformal infinity of the ambient cosmological metric. Due to the existence of a homothetic group, the bounding spacetime must be equipped not with the usual Euclidean metric topology but ...
Antoniadis, Ignatios, Cotsakis, Spiros
core +2 more sources
Classification of the Killing Vectors in Nonexpanding HH-Spaces with Lambda
, 2011 Conformal Killing equations and their integrability conditions for nonexpanding hyperheavenly spaces with Lambda are studied. Reduction of ten Killing equations to one master equation is presented.
Chudecki, Adam
core +1 more source
Wave-like Solutions for Bianchi type-I cosmologies in 5D [PDF]
, 2008 We derive exact solutions to the vacuum Einstein field equations in 5D, under the assumption that (i) the line element in 5D possesses self-similar symmetry, in the classical understanding of Sedov, Taub and Zeldovich, and that (ii) the metric tensor is ...
Apostolopoulos P S +17 more
core +2 more sources
Geometric aspects of transversal Killing spinors on Riemannian flows [PDF]
, 2008 We study a Killing spinor type equation on spin Riemannian flows. We prove integrability conditions and partially classify those Riemannian flows $M$ carrying non-trivial solutions to that equation in case $M$ is a local Riemannian product, a Sasakian ...
Ginoux, Nicolas, Habib, Georges
core +9 more sources
QFT on homothetic Killing twist deformed curved spacetimes
, 2011 We study the quantum field theory (QFT) of a free, real, massless and curvature coupled scalar field on self-similar symmetric spacetimes, which are deformed by an abelian Drinfel'd twist constructed from a Killing and a homothetic Killing vector field ...
A.P. Balachandran +16 more
core +1 more source
Third rank Killing tensors in general relativity. The (1+1)-dimensional case [PDF]
, 1998 Third rank Killing tensors in (1+1)-dimensional geometries are investigated and classified. It is found that a necessary and sufficient condition for such a geometry to admit a third rank Killing tensor can always be formulated as a quadratic PDE, of ...
C. Uggla +13 more
core +2 more sources
Concircular vector fields for Kantowski Sachs and Bianchi type III spacetimes
, 2017 This paper intends to obtain concircular vector fields of Kantowski Sachs and Bianch type III spacetimes. For this purpose, ten conformal Killing equations and their general solution in the form of conformal Killing vector fields are derived along with ...
Ali, Ahmad T +2 more
core +1 more source
Buffer or Conduit? Global Agri‐food Value Chains and Food Price Transmission
Canadian Journal of Agricultural Economics/Revue canadienne d'agroeconomie, EarlyView.Abstract In an era of volatile global markets, stabilizing domestic food prices has become increasingly critical. This paper examines how participation in global agri‐food value chains (GVCs) influences food price transmission through a robust two‐step regression framework.
Mohammed Beroud, Titus O. Awokuse
wiley +1 more source
IEEE AccessGeomagnetic field observation data are valuable resources for seismic geomagnetic research. However, the construction of subways, light railroads, and high-voltage direct current transmission lines in recent years has seriously affected the output data ...
Weifeng Shan +6 more
doaj +1 more source
New Symbolic Tools for Differential Geometry, Gravitation, and Field Theory [PDF]
, 2011 DifferentialGeometry is a Maple software package which symbolically performs fundamental operations of calculus on manifolds, differential geometry, tensor calculus, Lie algebras, Lie groups, transformation groups, jet spaces, and the variational ...
Acvevedo M. +5 more
core +4 more sources