Rotation of the polarization vector from distant radio galaxies in the perturbed FRW metric

Analysis of the correlation between the angular positions of distant radio galaxies on the sky and the orientations of their polarization vectors with respect to their major axes, indicates a dipolar anisotropy in the large scale. We consider a single mode of large-scale scalar perturbation to the FRW metric. Using Newman-Penrose formalism, we calculate the rotation of the galaxy major axis with respect to the polarization vector as the elliptic image and the polarization vector are carried through the perturbed space-time. The dependence of the rotation on the polar angular coordinate of the galaxy, is qualitatively similar to the claimed dipole pattern.Comment: 22 pages, 6 figures, references update

Growth and business cycles with imperfect credit markets

We study the process of growth and business cycles in an open economy which has access to international ¯nancial markets. The ¯nancial market imperfection originates from costly state veri¯cation and a positive probability of default on loans. The degree of credit market imperfection is endogenously derived. The results show that developed economies are able to borrow on easier terms than emerging countries. The credit market imperfection may cause some economies to fall into a development trap if the initial endowment of capital is too low. The ¯nancial market frictions also generate interesting business cycle dynamics. Financial market imperfections help in replicating the empirical fact that output growth shows positive autocorrelation at short horizons. The model also predicts that a poorer economy will experience a more severe and persistent e®ect on investment and output due to an exogenous shock. --Costly state verification,Credit markets,Growth,Business Cycles