The Analysis of the Gravitational Growth of the Matter, Thermal Evolution and the CMB anisotropies, which are related to the LargeScale Structures Formations.
Project/Area Number  06640352 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
Astronomy

Research Institution  Osaka University 
Principal Investigator 
GOUDA Naoteru Graduate School of Science, Osaka University, Associate Professor, 大学院・理学研究科, 助教授 (50202073)

Project Fiscal Year 
1994 – 1996

Project Status 
Completed(Fiscal Year 1996)

Budget Amount *help 
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1996 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1995 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1994 : ¥900,000 (Direct Cost : ¥900,000)

Keywords  Cosmology / LargeScale Structures in the Universe / Cosmic Microwave Background / Galaxy Formation / Gravitational Manybody Systems / 宇宙論 / 宇宙の大規模構造 / 宇宙背景輻射 / 銀河形成 / 重力多体系 
Research Abstract 
I analyzed the nonlinear dynamics of the gravitational growth of cosmological density fluctuations and the pattern of clustering which are much related to the largescale structure and galaxy formations. Furthermore I analyzed the merging history of dark haloes and galactic dynamics which are very important processes in the formations and evolutions of the galaxies. I got the following results by these analysis ; 1) I got the law of nonlinear Fouriermode coupling in the nonlinear growth of density fluctuations by the pseudospectral method. 2) I showed that the power index of the power spectrum of density fluctuations is determined only by the type of singularity which is classified in accord with the catastrophe theory in both twodimensional and threedimensional systems. Furthermore we found the relation between the power index of the twopoint correlation function and other quantities in the strongly nonlinear regime by the analysis of scaleinvariant solutions of the BBGKY equation. 3) We found the time scale of the relaxation to the quasiequilibrium state in the onedimensional selfgravitating manybody systems. Furthermore we showed that there are many quasiequilibrium states and the system wanders between the states. The distribution of time scale of transition is found to obey the power law. We believe that this is resulted from the fact that partial space which corresponds to a quasiequilibrium state distributes in the fractal form in the whole phase space. 4) We clarified the limitations of the PressSchechter formalism which is often used for estimate of the mass functions of dark haloes. Furthermore we showed that it is very important to consider the effect of spatial correlation in analyzing the merging history of dark haloes. 5) We estimated the difference between the Hubble constant observed in the local universe and the global Hubble constant by taking into account the bulk flows of galaxies.

Report
(5results)
Research Output
(26results)