2001 Fiscal Year Final Research Report Summary
Hierarchical Structure Formation of The Universe
| Project/Area Number |
11640235
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Astronomy
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| Research Institution | National Astronomical Observatory (2000-2001)
Kyoto University (1999) |
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Principal Investigator |
SUGAI Naoshi National Astronomical Observatory Divisiom of Theoretical Astrophysics, Professor, 理論天文学研究系, 教授 (70222057)
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| Project Period (FY) |
1999 – 2001
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| Keywords | COSOLOGY / LARGESCALESTRUCTRUE FORNATION / STRUCTURE FORMATION / REHATING / GALAXY FORMATION |
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| Research Abstract |
We have investigated the hierarchical structure formation of the universe. Followings are the results we have obtained. 1. By employing so-called semi-analytic galaxy formation scenario, the process of reheating of the inter-galactic medium (IGM) has been studied. The resultant ionized medium produces temperature anisotropies and polarization on the cosmic microwave background radiation (CMB). It has been shown that the amplitude and angular distribution of the temperature anisotropies and the polarization reveals the process of the galaxy formation. 2. Taking the cross-correlation between the gravitational lensing effect which is induced by the gravitational field and the temperature fluctuations of CMB which traces the ionized medium, we have pointed out the possibility to reveal the relation between the structure formation by gravity and the galaxy formation. 3. We have set a very stringent constraint on the neutrino mass from the fact that the large scale structure formation is prevented by the existence of the massive neutrinos due to their streaming motion.4. We have invesitated the weak non-linear evolution of density and velocity perturbations during the recombination epoch. 5. We have studied the weak non-linear evolution of density and velocity fields in the matter-dominated universe. We have concentrated on the statistical nature of the velocity field. Moreover, we have compared our method with the direct numerical simulations, i.e., N-body simulations to test the validity of the method. 6. We have investigated the nature of the density perturbations induced by inflation of the early universe. The relation with the large scale structure formation has been studied too. 7. We have revealed the relation between the global topology of the universe and CMB temperature fluctuations, which are the seeds of the hierarchical structure of the universe.
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