Project/Area Number  07640366 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
素粒子・核・宇宙線

Research Institution  TOHOKU UNIVERSITY 
Principal Investigator 
FUTAMASE Toshifumi Tohoku University, Graduate School of Science, Professor, 大学院・理学研究科, 教授 (20209141)

CoInvestigator(Kenkyūbuntansha) 
KASAI Masumi Hirosaki University, Department of Physics, Associate Professor, 理学部, 助教授 (30204358)

Project Fiscal Year 
1995 – 1996

Project Status 
Completed(Fiscal Year 1996)

Budget Amount *help 
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1996 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1995 : ¥1,200,000 (Direct Cost : ¥1,200,000)

Keywords  Gravitational Lens / Giant Luminous Arc / cB58 / Averaging / 重力レンズ / 巨大ルミナスアーク / CB58 / 時空の平均化 / 増光バイアス / 非一様宇宙モデル 
Research Abstract 
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.
