Project/Area Number  06640426 
Research Category 
GrantinAid for Scientific Research (C)

Section  一般 
Research Field 
素粒子・核・宇宙線

Research Institution  National Astronomical Observatory 
Principal Investigator 
KAJINO Toshitaka National Astronomical Observatory Division of Theoretical Astrophysics, Associate Professor, 理論天文学研究系, 助教授 (20169444)

CoInvestigator(Kenkyūbuntansha) 
YOSHII Yuzuru University of Tokyo Institute of Astronomy, Professor, 天文教育研究センター, 教授 (00158388)
TSUJIMOTO Takuji National Astronomical Observatory Division of Theoretical Astrophysics, Assistan, 位置天文・天体力学研究系, 助手 (10270456)
OGASAWARA Ryuusuke National Astronomical Observatory Division of Theoretical Astrophysics, Associat, 理論天文学研究系, 助教授 (30177109)
MIYAMA Shoken National Astronomical Observatory Division of Theoretical Astrophysics, Professo, 理論天文学研究系, 教授 (00166191)
INUTSUKA Shuichiro National Astronomical Observatory Division of Theoretical Astrophysics, Assistan, 位置天文・天体力学研究系, 助手 (80270453)

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 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1995 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1994 : ¥700,000 (Direct Cost : ¥700,000)

Keywords  phase transition / structure of vacuum / QCD / quark & hadron / chiral symmetry / color confinement / nucleation / evolution of galaxy / 宇宙相転移 / 真空の構造 / クォーク・ハドロン / カイラル対称性 / クォーク閉じ込め / 核化 / 銀河の進化 / クオーク・ハドロン / クオーク閉じ込め / 銀河化学進化 / 初期宇宙 / クォーク / ハドロン / 相転移 / 真空 
Research Abstract 
In the first two years 1994 and 1995 we constructed theoretical framework for the studies of cosmological first order phase transition. This consists of two parts. The first is to describe the nucleation of hardronic bubbles and their growth process during the supercooling epoch of the phase transition, and the second is to formulate the process of baryon number transfers through the phase boundary after the Universe was reheated to the critical temperature. In addition to these theoretical studies, we constructed in this year 1996 the effective phenomenological model Lagrangian for Quantum Chromodynamins (QCD) which is applied to the vacuum at finite temperature and density. We took account of all recent theoretical products from the lattice gauge simulations of which can describe spontaneous chiral symmetry breaking and also color confinement. We combined these theoretical models with one another and tried to solve the integrodifferential equations for the time variation of baryon num
… More
ber densities in the hightemperature QGP phase and lowtemperature hadron phase numerically. We used big computers and workstations at NAO in performing this program. We then found that the inhomoegenous baryon number densities which arises eventually from the first order cosmological QCD phase transition have very huge density contrast as large as a million or more and that the mean separation distance between the fluctuations ranges from ten meters to the horizon scale at T=1 MeV nucleosynthesis epoch. These fluctuation distance scales depend strongly on the fundamental QCD parameters. The primordial nucleosynthesis in the baryon inhomogeneous cosmology turns out to be dramatically different from the homogeneous bigbang nucleosynthesis. The most striking result is that our cosmological model can allow very large universal average baryon density, as was suggested from the recent astronomical observations in rich clusters or superclusters. We applied these primordial abundances to the studies of chemical evolution of galaxies and proposed several astronomical observations in order to test our cosmological model of inhomogeneous baryon density Universe. Less
