Cosmological Constant and the Evolution of the Universe

1)超新星爆炸产生的中微子本底辐射Superkamiokande计划最近启动，它可以通过超新星爆炸观测到中微子遗迹。本文利用星系化学演化模型，详细研究了遗迹中微子的光谱。总通量强烈地依赖于哈勃参数，但对宇宙学常数的依赖很弱。我们发现在相同的平坦宇宙模型中，λ =0时的通量比λ * o时的小。2）原始核合成原始核合成是决定重子密度的最好工具。近年来，随着观测技术的进步，观测结果指出，简单的宇宙学模型存在一个问题。有些人称这个问题为宇宙中的“危机”。因此，我们考虑了轻子不对称宇宙中的理论误差，用Monte Calro模拟方法统计估计了轻元素的末位分数。结果表明，简并参数和重子密度的最佳值为0.043（]SY ±-。[）0.040和0.015（]SY. ±. 0.006-0.003（CL.95%）。

1) Neutrino Background Radiation due to Supernove ExplosionRecently Superkamiokande project has started and it can observe the relic neutrino through supernove explostion. We investigated carefuly the spectrum of relic neutrino using the model for the chemical evolution of galaxies. The total flux depends strongly on the Hubble parameter, but weakly on the cosmological constant. We found that in the same flat universe model the flux in lambda=0 is smaller than that in lambda*o.2) Primordial NucleosynthesisThe primordial nucleosynthesis is best tool for deciding the baryon density. Recently, associated with the progress of techonology in obsevational field, the obsevational result pointed out that the simple model for cosmology has a trouble point. Some of people call the problem as 'crisis' in the universe. Hence, we taken account of the theoretical error in the lepton asymmetry universe and estimeted statistically the final fraction of the light elements by Monte Calro simulation. The result is that the best values for the degenerate parameter and the baryon density are 0.043(]SY.+-。[)0.040 and 0.015(]SY.+-。[)0.006-0.003 (CL.95 percent).