论文标题
在共同的物理耦合框架内测试变化的$λ$模型
Testing a varying-$Λ$ model for dark energy within Co-varying Physical Couplings framework
论文作者
论文摘要
同时变化的物理耦合（CPC）框架是一个修改的重力设置，假设Einstein场方程中，其中$ \ {g，c，λ\} $被提升为时空功能。 Bianchi身份和应力 - 能量张量保护的需求纠缠了耦合$ \ {g，c，λ\} $的可能变化，这些变化被迫由一般约束（GC）所决定的。在本文中，我们探讨了一个宇宙学模型，其中$ g $，$ c $和$λ$是尊重CPC框架GC的红移功能。我们假设在比例因子$ a $方面，$λ$的线性参数化。我们使用ansatz $ \ dot {g}/g =σ\ left（\ dot {c}/c \ right）$用$σ= $ constand推断出$ c = c（z）$和$ g = g = g（z）$的功能形式。我们表明，这种变化 - $ \ {g，c，λ\} $模型拟合sne ia data和$ h（z）$数据，$σ= 3 $。模型参数可以限制以描述背景级别的暗能量。
The Co-varying Physical Couplings (CPC) framework is a modified gravity set up assuming Einstein Field Equations wherein the quantities $\{G,c,Λ\}$ are promoted to space-time functions. Bianchi identity and the requirement of stress-energy tensor conservation entangle the possible variations of the couplings $\{G,c,Λ\}$, which are forced to co-vary as dictated by the General Constraint (GC). In this paper we explore a cosmological model wherein $G$, $c$ and $Λ$ are functions of the redshift respecting the GC of the CPC framework. We assume a linear parametrization of $Λ$ in terms of the scale factor $a$. We use the ansatz $\dot{G}/G = σ\left( \dot{c}/c \right)$ with $σ=$ constant to deduce the functional forms of $c=c(z)$ and $G=G(z)$. We show that this varying-$\{G,c,Λ\}$ model fits SNe Ia data and $H(z)$ data with $σ= 3$. The model parameters can be constrained to describe dark energy at the background level.
