Determination of Cosmological Constant by Statistical Lens and Effect of Inhomogeneities of the Universe on the Cosmic Age

点击翻译按钮获取中文摘要

Giant luminous arcs has been known as gravitational lens phenomena due to cluster of galaxies. However there is a big discrepancy between theoretical prediction of the expected number and the observed number of the arcs in a certain number of the cluster of goalaxies. We have claculated the expected number of arcs based on the recent observation of distant galaxies. The expected number we have obtained is much more than the previous estimate, but is still less than the observed one. However according our calculation we have obtained a feeling that it is not impossible to agree with the observed number if we improved mass distribution for the cluster and include the cosmological constant.We pointed out a new new lensing phenomena due to cluster of galaxy which is distored much, but is very much magnified. We show that a certain restriction on the cosmological parameters, in particular cosmological constant, is obtained using this kind of lensing. As an example of this kind of phenomena, we analyze cB58 and obtained a restriction on the cosmological constant.We have also proposed two different methods to average Einstein equation to construct locally inhomogeneous universe model. The method is applied to derive the graviational lens equation in a realistic cosmological circumstances.