Cosmological Simulation of Gravitational Weak Lensing in Open Models

Cosmological simulation of gravitational weak lensing in open models with (Ω0, λ0) = (0.2, 0) and (0.4, 0) is treated using the direct integration method, which is independent of the multi-lens-plane method. Statistical averages of optical quantities (the convergence, shear, and amplification) are derived for ray bundles passing through the clumpy universe, in which the initial state has the CDM spectrum with the power n = 1, and all particles are regarded as equivalent (compact) lens objects with a galactic size. The compact lens objects consist of galaxies and dark matter particles. The evolution of the spatial mass distribution is given by N-body simulations in a tree-code. This paper is an extension of our previous one in flat models. The behaviors of optical quantities are shown in comparison with a low-density flat model with (0.2, 0.8). It is found as a result that (1) optical quantities in the open model increase with Ω0, and (2) they are larger than those in the flat model with the same Ω0, and the difference is comparable with that between two open models with Ω0 = 0.2 and 0.4. The comparison of the optical quantities with the corresponding observed ones will give us some information on the observational value of Ω0.