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arXiv 2209.04037gr-qc
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$f(Q,T)$引力中的精粹宇宙和宇宙加速

Quintessence Universe and cosmic acceleration in $f(Q,T)$ gravity

M. Koussour, N. Myrzakulov, S. H. Shekh, M. Bennai

摘要:

宇宙加速和暗能量的问题是目前科学界提出的谜团之一,广义相对论还没有能够解决。在这项工作中,我们已经考虑了替代模型来解释这种晚时加速在平坦的Friedmann-Lemaiden/tre-Robertson-Walker(FLRW)宇宙的框架内的$% f\left(Q,T\right) $ \修改的引力理论(其中$Q$是非度规性和$T$是能量动量张量的迹)最近提出的Xu等人(Eur. Phys. J. C 79(2019)708),它是$f\left( Q\right) $重力的扩展,增加了$T$项。在这里,我们假定一个特定形式的$f\left( Q,T\right) =αQ+βQ^{2}+γT$,其中$% α$,$β$和$γ$是自由模型参数,并通过假设宇宙时间-红移关系为$t(z)=\frac{% nt_{0}}{m}g(z)$,它产生形式为$H(z)=\frac{% mH_{0}}{m+n}\left[ \frac{1}{g(z)}+1\right] $的哈勃参数,其中$m$和$n$是非负常数,我们找到了它们的最佳值,使用57个数据点的哈勃参数$H\left( z\right) $。另外,我们还计算了减速参数$% \left( q\right) $、能量密度$\left( ρ\right) $、压力$% \left(p\right) $和EoS参数$\left( ω\right) $等宇宙学参数的行为,并与观测结果进行了比较。为了保证结果的正确性,我们研究了能量条件和加加速度参数。最后,我们发现,我们的模型的行为类似的精髓宇宙。

英文摘要:

The problem of cosmic acceleration and dark energy is one of the mysteries presently posed in the scientific society that general relativity has not been able to solve. In this work, we have considered alternative models to explain this late-time acceleration in a flat Friedmann-Lemaî% tre-Robertson-Walker (FLRW) Universe within the framework of the $% f\left(Q,T\right) $\ modified gravity theory (where $Q$ is the non-metricity and $T$ is the trace of the energy-momentum tensor) recently proposed by Xu et al. (Eur. Phys. J. C 79 (2019) 708), which is an extension of $f\left( Q\right) $ gravity with the addition of the $T$ term. Here, we presume a specific form of $f\left( Q,T\right) =αQ+βQ^{2}+γT$ where $% α$, $β$ and $γ$ are free model parameters, and obtained the exact solutions by assuming the cosmic time-redshift relation as $t(z)=\frac{% nt_{0}}{m}g(z)$ which produces the Hubble parameter of the form $H(z)=\frac{% mH_{0}}{m+n}\left[ \frac{1}{g(z)}+1\right] $ where $m$ and $n$ are the non-negative constants, we find the best values for them using 57 data points of the Hubble parameter $H\left( z\right) $. Also, we find the behavior of different cosmological parameters as the deceleration parameter $% \left( q\right) $, energy density $\left( ρ\right) $, pressure $% \left(p\right) $ and EoS parameter $\left( ω\right) $ and compare them with the observational results. To ensure the validity of the results, we studied the energy conditions along with jerk parameter. Finally, we find that our model behaves similarly to the quintessence Universe.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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