QSO-GALAXY CORRELATIONS INDUCED BY WEAK LENSING IN ARBITRARY FRIEDMANN-LEMAITRE COSMOLOGIES

We calculate the angular cross-correlation function between background QSOs and foreground galaxies induced by the weak lensing effect of la rge-scale structures. Results are given for arbitrary Friedmann-Lemait re cosmologies. The non-linear growth of density perturbations is incl uded. Compared with the linear growth, the non-linear growth increases the correlation amplitude by about an order of magnitude in an Einste in-de Sitter universe, and by even more for lower Omega(0). The depend ence of the correlation amplitude on the cosmological parameters stron gly depends on the normalization of the power spectrum. The QSO-galaxy cross-correlation function is most sensitive to density structures on scales in the range (1-10)h(-1) Mpc, where the normalization of the p ower spectrum to the observed cluster abundance appears most appropria te. In that case, the correlation strength changes by less than a fact or of less than or similar to 2 when Omega(0) varies between 0.3 and 1 , quite independent of the value of Omega(A). For Omega(0) less than o r similar to 0.3, the correlation strength increases with decreasing O mega(0), and it scales approximately linearly with the Hubble constant h.