修正的Chaplygin气体暗能量及其Om几何诊断法

Modified Chaplygin gas as dark energy and the Om geometrical diagnostic

在标准宇宙学模型框架下,为解释当前宇宙的加速膨胀,人们引入了具有负压强的暗能量。修正的Chaplygin气体(MCG)模型是一种暗能量和暗物质的统一模型,可以用来解释当前宇宙的加速膨胀。考虑在暗能量和暗物质之间没有相互作用和存在相互作用这两种情况下,MCG模型的动力学方程和能量密度随红移z的演化,通过绘图分析得到其能量转化规律。进一步应用Om几何诊断方法,将MCG模型与宇宙学常数模型ΛCDM和Chaplygin气体(GCG)模型加以区分。

In order to explain the accelerated universe in the framework of standard cosmology,the dark energy with negative pressure is introduced.The modified Chaplygin gas（MCG）model is proposed as an unified model of dark energy and dark matter,which can be used to interpret the accelerated universe at the present time.In this paper,the dynamics of MCG and the change rate of energy densities with and without interaction,are investigated by analyzing their evolutionary curves.Furthermore,the MCG model can be differentiated from other models such as theΛCDM and the GCG models by means of the Omgeometrical diagnostic.