论文标题
变色龙重力的宇宙学
Cosmography of chameleon gravity
论文作者
论文摘要
本文讨论了变色龙重力的特定模型，其中标量字段的指数为$ v = m^{4} \ exp（\ frac {αdact} {m_ {pl}}）$，并且指数偶联到宇宙的物质成分$ρ_{m} \ exp（\ frac {βϕ} {m_ {pl}}）$。我们发现模型的四个（原则上没有）参数与前五个cosmographic参数（可以用哈勃参数及其前四个衍生物编写）之间的关系。如果已知此类cosmographic参数，那么我们呈现代数关系，该代数可用于根据cosmographic来得出自由参数。我们表明，如果已知Chameleon参数$β$和耦合常数$α$，则确定比例因子$ Q $的第三个衍生物非常重要。另一方面，如果没有提出关于$（α，β）$的任何建议，则可以通过测量量表因子的前五个衍生物并测试理论的有效性来重建模型的自由参数，仅通过其前六个衍生物才能自动确定参数$（α，β）$也可以自动确定。当它动态接近其临界点时，我们还发现了模型参数与模型参数之间的关系。
The paper discusses a particular model of chameleon gravity where the scalar field has an exponential as $V=M^{4}\exp(\frac{αϕ}{M_{pl}})$ and an exponential coupling to the matter density component of the Universe as $ρ_{m}\exp(\frac{βϕ}{M_{pl}})$. We finds the relations between the four (in principle free) parameters of the model and the first five cosmographic parameters (which can be written in terms of the Hubble parameter and its first four derivatives). If such cosmographic parameter are known then the we present the algebraic relations which can be used to derive the free parameters in terms of the cosmographic ones. We show that, determining the third derivative of scale factor $Q$ is of great importance if the chameleon parameter $β$ and coupling constant $α$ are known. On the other hand, if nothing can be proposed about $(α,β)$, reconstructing the free parameters of the model can be done by measuring the first five derivatives of the scale factor and testing the validity of theory is only possible by its first six derivatives, so that the parameters $(α,β)$ will also be determined automatically. We also find relation between cosmographic parameters and parameters of the model when it dynamically approaches its critical points.
