论文标题
在F（Q，T）重力中具有观察约束的过境宇宙学模型
Transit cosmological models with observational constraints in f(Q, T) gravity
论文作者
论文摘要
该宇宙学模型是对重力（Q，t）$重力理论的研究，该理论最近提出了Xu {\ it等}（Eur。Phys。J.C {\ Bf 79}，708（2019））。在这种重力理论中，该动作包含一个任意函数$ f（q，t）$，其中$ q $是非物质的，而$ t $是物质流体的能量弹药张量的痕迹。在我们的研究中，我们采用了$ f（q，t）$ q $的函数$ q $，$ t $ in $ f（q，q，t）=αq+βq^{2}+γt$其中$α$，$β$和$β$和$β$是模型参数，由$ f（r，t）$ GREAT激励。我们在Friedmann-Lemaitre-Robertson-Walker（FLRW）Universe中获得了各种宇宙学参数。哈勃参数$ h $，减速参数$ q $等在比例因素方面以及通过限制能源保存法律的红移$ z $方面。对于模型上的观察约束，我们使用可用数据集（例如Hubble数据集）$ H（Z）$，关节光曲线分析（JLA）数据集（JLA）数据集和Union $ 2.1 $ $ 2.1 $汇编，通过应用$ r^{2} $ - 测试$ - 测试公式。我们计算了各种观察参数的当前值，即。 $ h_ {0} $，$ q_ {0} $，$ t_ {0} $和statefinder参数$（s，r）$，这些值非常接近标准宇宙学模型。另外，我们已经观察到，减速参数$ q（z）$显示签名 - 浮动（过渡）$ 0.423 \ leq z_ {t} \ leq0.668 $，通过其从减速到加速度扩展为州（EOS）$ -1.071 $ 0.071 \ leq for-0.96 $ 0.96 $ 0.96 $ 0.96 $ 0.96 $ 0.96 $ 0.96 $ 0.96 $ 0.96.99668 $。 z \ leq3 $。
This cosmological model is a study of modified $f(Q,T)$ theory of gravity which was recently proposed by Xu {\it et al.} (Eur. Phys. J. C {\bf 79}, 708 (2019)). In this theory of gravity, the action contains an arbitrary function $f(Q,T)$ where $Q$ is non-metricity and $T$ is the trace of energy-momentum tensor for matter fluid. In our research, we have taken the function $f(Q,T)$ quadratic in $Q$ and linear in $T$ as $f(Q,T)=αQ+βQ^{2}+γT$ where $α$, $β$ and $γ$ are model parameters, motivated by $f(R,T)$ gravity. We have obtained the various cosmological parameters in Friedmann-Lemaitre-Robertson-walker (FLRW) Universe viz. Hubble parameter $H$, deceleration parameter $q$ etc. in terms of scale-factor as well as in terms of redshift $z$ by constraining energy-conservation law. For observational constraints on the model, we have obtained the best-fit values of model parameters using the available data sets like Hubble data sets $H(z)$, Joint Light Curve Analysis (JLA) data sets and union $2.1$ compilation of SNe Ia data sets by applying $R^{2}$-test formula. We have calculated the present values of various observational parameters viz. $H_{0}$, $q_{0}$, $t_{0}$ and statefinder parameters $(s,r)$, these values are very close to the standard cosmological models. Also, we have observed that the deceleration parameter $q(z)$ shows signature-flipping (transition) point within the range $0.423\leq z_{t}\leq0.668$ through which it changes its phase from decelerated to accelerated expanding universe with equation of state (EoS) $-1.071\leqω-0.96$ for $0\leq z\leq3$.
