Energy Distribution of a G\"{o}del-Type Space-Time

We calculate the energy and momentum distributions associated with a G\"{o}del-type space-time, using the well-known energy-momentum complexes of Landau and Lifshitz and M{\o}ller. We show that the definitions of Landau and Lifshitz and M{\o}ller do not furnish a consistent result.Comment: LaTex, no figure

M{\o}ller Energy-Momentum Complex of a Static Axially Symmetric Vacuum Space-Time

The energy and momentum densities associated with the Weyl metric are calculated using M{\o}ller's energy-momentum complex. These results are compared with the results obtained by using the energy-momentum complexes of Einstein, Landau and Lifshitz, Papapetrou and Bergmann. We show that the aforementioned different prescriptions and that of M{\o}ller do not give the same energy density, while give the same momentum density.Comment: LATEX, 9 pages, no figures, an improved version, references added, corrections [Admin note: substantial overlap with gr-qc/0403097, gr-qc/0404108 , gr-qc/0303009 , hep-th/0311050

The two sector endogenous growth model: an atlas

In this paper we investigate the underlying structure of the Lucas (1988) endogenous growth model. We derive analytically, the restrictions on the parameter space that are necessary and sufficient for the existence of balanced growth paths and saddle-path stable local dynamics. We demonstrate that in contrast to the original model, with the addition of an external effect and depreciation in the human capital sector, the Lucas model can be made consistent with the high degrees of intertemporal elasticities of substitution increasingly estimated in the empirical literature even if there is a significant degree of increasing returns to scale in the physical production sector of the economy. Finally we demonstrate that for a given baseline rate of steady state growth, with the inclusion of modest degrees of depreciation and external effects to the human capital production process, the model can accommodate the widest possible range of economies including those characterized by low discount factors, high elasticities of intertemporal substitution, increasing returns in the final goods sector, and also both the high rates of population growth and steady state per-capita output growth we observe in many parts of the world today