在高维动力系统中分析耦合为Q=αHρ_m的DBI暗能量模型

Analysis of DBI Model with Coupling Q = αHρ_m in High-dim Dynamical System

在二维和三维Dirac-Bom-Infeld(DBI)暗能量宇宙模型的基础上,从高维动力系统的角度重新讨论宇宙的动力学演化;即讨论同时含有{x,y,γ,λ1,λ2}的五维自洽动力系统的相空间演化。在宇宙学参数限制条件下,又通过稳定点判别法,从十个临界点中,选出一个三维稳定点,和一个五维稳定点。并且针对五维稳定点进行宇宙学演化的分析,发现晚期宇宙的状态与耦合参数α的取值相关,进而分析在不同取值下,晚期宇宙的特征。

Based on 2-dim and 3-dim Dirac-Bom-Infeld (DBI) dark energy model, the cosmological evolution was discussed from the view of high-dim dynamic system, which contained five phases{x,y,γ,λ1,λ2}in all. Under the constrain of cosmological and stability discrimination, a 3-dim stable point and a 5-dim stable point were selected from all ten critical points. By the analysis of the 5-dim stable point, it was found that the state of the late time universe depended on the coupling parameterα. the late time state was further analyzed by different value of α.