宇宙学模型简并与分立性质研究

Degeneracy and discreteness in cosmology models

从标准宇宙学模型(ΛCDM)出发,结合多种拟合函数开始讨论其中的简并与分离性质.我们使用了已观测到的哈勃参数(OHD)和Ia型超新星(SNeIa)的数据来验证这个性质.为了解释拟合过程中的离散性,我们定义了一个因子G来测试每一个数据点对拟合结果的影响,并且分析因子G的优点之处.事实上,因子G不依赖于任何一个特定模型,即是说它可以被推广到任何一种模型.研究结果表明:绝对值较高的G在拟合过程中有更好的区分能力,也就是能把参数限制在更小的置信区间内.因此,我们认为因子G是可以设定在使用观测数据拟合模型中的标准新方法,这有助于我们更深入的理解概率和宇宙学.

This paper deals with the standard cosmological model,then specific fitting functions are considered to explore the degenerate and discrete phenomenon.Factor Gis defined to describe discreteness when fitting models and testing influence on fitting results and analysis goodness of G.It is found that factor G is independent of specific fitting function and can be generalized to any fitting functions.Therefore it is a reasonable explanation of degeneracy and discreteness in some aspects.Data indicate that a higher absolute G value shows a better capability to distinguish models.In model fitting,this would mean smaller confidence intervals of parameters.Consequently,factor Gis a new method to set criterion when using observed data to fit model,which helps to have a more profound understanding of probability and cosmology.