21 research outputs found
Charged Dilaton, Energy, Momentum and Angular-Momentum in Teleparallel Theory Equivalent to General Relativity
We apply the energy-momentum tensor to calculate energy, momentum and
angular-momentum of two different tetrad fields. This tensor is coordinate
independent of the gravitational field established in the Hamiltonian structure
of the teleparallel equivalent of general relativity (TEGR). The spacetime of
these tetrad fields is the charged dilaton. Our results show that the energy
associated with one of these tetrad fields is consistent, while the other one
does not show this consistency. Therefore, we use the regularized expression of
the gravitational energy-momentum tensor of the TEGR. We investigate the energy
within the external event horizon using the definition of the gravitational
energy-momentum.Comment: 22 Pages Late
Separation of the Longitudinal and Transverse Cross Sections in the p(e, e′K+)Λ and p(e, e′K+)Σ0 Reactions
We report measurements of cross sections for the reaction p(e,e′K+)Y, for both the Λ and Σ0 hyperon states, at an invariant mass of W =1.84 GeV and four-momentum transfers 0.5 < Q2 < 2 (GeV/c)2. Data were taken for three values of virtual photon polarization ε, allowing the decom- position of the cross sections into longitudinal and transverse components. The Λ data is a revised analysis of prior work, whereas the Σ0 results have not been previously reported
Adaptation of Agricultural and Food Systems to Climate Change: An Economic and Policy Perspective
Adaptation of agricultural and food systems to climate change involves private and public investment decisions in the face of climate and policy uncertainties. The authors present a framework for analysis of adaptation as an investment, based on elements of the economics, finance, and ecological economics literatures. They use this framework to assess critically impact and adaptation studies, and discuss how research could be designed to support public and private investment decisions. They then discuss how climate mitigation policies and other policies may affect adaptive capacity of agricultural and food systems. They conclude with an agenda for public research on climate adaptation. Copyright 2010, Oxford University Press.