WEAK LENSING CORRELATIONS IN OPEN AND FLAT UNIVERSES

Correlations between the magnification or polarization of background s ources, induced by gravitational lensing due to their large-scale stru cture, and the positions of foreground galaxies, are investigated. We find that the amplitude of those correlations is enhanced with respect to those for a single population. We analyse the dependence of the co rrelations with the density parameter Ohm considering a non-linear evo lution of the matter-power spectrum. The contribution of linear evolut ion is negligible at scales below several arcmin. Detailed results reg arding the dependence of the correlations on the redshift of the foreg round and background populations for different cosmological models are presented. The effect reaches its maximum amplitude for foreground po pulations with relatively small redshifts due to the rapid increase of the non-linear matter-power spectrum at recent times.