We have investigated the spatially homogeneous and isotropic Friedmann–Robertson–Walker (FRW) universe filled with barotropic fluid and dark energy in the framework of the Brans–Dicke theory of gravitation. Here we have discussed three models: (i) law of variation for Hubble’s parameter, which leads to a constant value of deceleration parameter, (ii) hybrid expansion law model, and (iii) special form of deceleration parameter model. We have found that among all these derived models, the most suitable standard cosmological model according to the recent cosmological observations is the model with special form of deceleration parameter.

中文翻译：

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用 Brans-Dicke 引力理论中暗能量的可变 EoS 参数加速宇宙

我们在 Brans-Dicke 引力理论的框架内研究了空间均匀且各向同性的 Friedmann-Robertson-Walker (FRW) 宇宙，该宇宙充满了正压流体和暗能量。这里我们讨论了三个模型：(i) 哈勃参数的变化规律，导致减速参数的恒定值，(ii) 混合膨胀规律模型，以及 (iii) 减速参数模型的特殊形式。我们发现，在所有这些推导出的模型中，根据最近的宇宙学观测，最合适的标准宇宙学模型是具有特殊形式的减速参数的模型。