论文标题

混合和对数电触电引力的加速宇宙

Accelerating Universe in Hybrid and Logarithmic Teleparallel Gravity

论文作者

Mandal, Sanjay, Bhattacharjee, Snehasish, Pacif, S. K. J., Sahoo, P. K.

论文摘要

电触电引力是一种修改的重力理论,在动作中,基础几何形状的RICCI标量$ r $被任意功能形式的扭转标量$ t $所取代。这样一来,$%f(t)$重力中的宇宙学大大简化了这一事实,即$ t $仅包含Vierbeins的第一个衍生物。这篇文章利用了$ f(t)$重力的这种吸引人的性质和当前的宇宙学场景,来自形式的混合和对数电触电引力模型$%f = e^{mt} t^n $和$ f = d \ f = d \ log(bt)$,其中$ n $,$ n $,$ d $和$ b $和$ b $是免费的参数。我们使用$χ^{2} $限制了一个自由度的减速参数的积极进取的参数化,从Redshift范围内的Hubble数据的57个数据点$ 0.07 <z <z <2.36 $,以获取触发,密度和EOS参数的表达,以获取远程电视膜模型的压力,密度和EOS参数。我们发现减速参数可以体验$χ^{2} $的签名翻转,以$ z_ {tr} \ simeq0.6 $的$χ^{2} $值,这与最新的Planck测量值一致。接下来,我们提出了这种参数化的几何诊断,以了解暗能量的性质及其偏离$λ$ CDM宇宙学。最后,我们研究了能量条件,以检查两个远程重力模型的参数空间的一致性。我们发现两种模型都违反SEC,这是获得加速宇宙的重要配方。

Teleparallel gravity is a modified theory of gravity for which the Ricci scalar $R$ of the underlying geometry in the action is replaced by an arbitrary functional form of torsion scalar $T$. In doing so, cosmology in $% f(T)$ gravity becomes greatly simplified owing to the fact that $T$ contains only the first derivatives of the vierbeins. The article exploits this appealing nature of $f(T)$ gravity and present cosmological scenarios from hybrid and logarithmic teleparallel gravity models of the form $% f=e^{mT}T^n $ and $f=D\log(bT)$ respectively, where $m$, $n$, $D$ and $b$ are free parameters constrained to suffice the late time acceleration. We employ a well motivated parametrization of the deceleration parameter having just one degree of freedom constrained with a $χ^{2}$ test from 57 data points of Hubble data set in the redshift range $0.07<z<2.36$, to obtain the expressions of pressure, density and EoS parameter for both the teleparallel gravity models and study their temporal evolution. We find the deceleration parameter to experience a signature flipping for the $χ^{2}$ value of the free parameter at $z_{tr}\simeq0.6$ which is consistent with latest Planck measurements. Next, we present few geometric diagnostics of this parametrization to understand the nature of dark energy and its deviation from the $Λ$CDM cosmology. Finally, we study the energy conditions to check the consistency of the parameter spaces for both the teleparallel gravity models. We find the SEC to violate for both the models which is an essential recipe to obtain an accelerating universe.

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