宇宙熵密度在能量条件上的研究

RESEARCH ON ENERGY CONDITIONS USING ENTROPY DENSITY BUDGET OF THE UNIVERSE

在标准的FLRW宇宙学模型中,能量条件对光度距离模数给予了不依赖于模型的边界约束.首先我们基于Egan&Lineweaver估算了宇宙熵密度随着红移的演化.进而,对能量条件和宇宙的熵密度展开了更深一步的分析.定义了一个能量条件函数fij,然后分别讨论它们以研究能量条件成立的范围,探讨了fij在常数状态非常和时间依赖性状态非常模型下,对宇宙学参数的依赖性.发现物质密度参数Ωm越高fij的值越大.此时,也讨论了能量条件在数学上成立的范围.最终,对能量条件和宇宙熵估计做了比较.我们发现除了SEC中的ρ+3p>0在s/s0<5.39违背以外,其他条件都成立.

Energy conditions provide model-independent bounds for behavior of distance modulus in the standard cosmological model of Friedmann-Lematre-Robertson-Walker（FLRW）.In the present paper,evolution of entropy density of the universe upon red-shift was estimated based on the method of Egan and Lineweaver.Extensive analysis was done of the energy conditions based upon the entropy density of the universe.An energy condition function fij was defined and discussed.Dependency of fij on cosmological parameters in constant equation of state model and time-dependent equation of state model was discussed.It was found that the higher the Ωm the larger the fij.The range in which energy conditions held was established.The energy conditions were compared with entropy budget of the universe.It was found that all the condition was followed but for the ρ＋3p0 in SEC at s/s05.39.