论文标题
在修改的重力和观察性约束中的有效状态方程
Effective equation of state in modified gravity and observational constraints
论文作者
论文摘要
在本文中，大量粘度是在修改的重力模型中引入的。重力动作具有一般的$ f（r，t）$形式，其中$ r $和$ t $分别是曲率标量和能量动量张量的痕迹。已经在宇宙学演化中研究了一个有效的状态方程（EOS）。在当前情况下，可以一般获得与红移相关的哈勃参数。讨论了减速参数$ q $的作用和状态参数$ω$的方程，以解释宇宙的延迟加速扩展。为我们获得的模型讨论了状态基础参数和OM诊断分析，以区分其他暗能量模型，并分析能量条件和模型的声音速度。我们还通过详细的$ 580 $ IA类型超新星的详细最大似然分析从Union $ 2.1 $汇编数据集和更新的$ 57 $ HUBBLE数据集（$ 31的数据点（来自差异时代的数据点$ 31 $ 26 $ $ 26 $），我们还通过数字研究了该模型。正是由于努力发现，目前的模型与观察结果非常吻合。
In this article, the bulk viscosity is introduced in a modified gravity model. The gravitational action has a general $f(R,T)$ form, where $R$ and $ T $ are the curvature scalar and the trace of energy momentum tensor respectively. An effective equation of state (EoS) has been investigated in the cosmological evolution with bulk viscosity. In the present scenario, the Hubble parameter which has a scaling relation with the redshift can be obtained generically. The role of deceleration parameter $q$ and equation of state parameter $ω$ is discussed to explain the late-time accelerating expansion of the universe. The statefinder parameters and Om diagnostic analysis are discussed for our obtained model to distinguish from other dark energy models together with the analysis of energy conditions and velocity of sound for the model. We have also numerically investigated the model by detailed maximum likelihood analysis of $580$ Type Ia supernovae from Union $ 2.1$ compilation datasets and updated $57$ Hubble datasets ($31$ data points from differential age method and $26$ points from BAO and other methods). It is with efforts found that the present model is in good agreement with observations.
