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Bianchi type-I cosmological model in Sáez-Ballester theory with variable deceleration parameter
Astrophysics and Space Science ( IF 1.9 ) Pub Date : 2021-05-24 , DOI: 10.1007/s10509-021-03952-4
R. K. Mishra , Heena Dua

The present study is outcome of investigation of Bianchi type-I cosmological model in Sáez-Ballester theory of gravity with variable deceleration parameter. Here, we have also considered variable cosmological constant \(\Lambda\) which may be a probable candidate to discuss dark energy. The solution of the field equations has been found using variable deceleration parameter i.e. \(q=-1+\beta H\) (with \(\beta\) as a positive constant and \(H\) as Hubble parameter) (Tiwari et al. in Eur. Phys. J. Plus 132:1–9, 2017) and suitable assumption of variable form of cosmological constant. We have expressed cosmological parameters such as Hubble parameter, deceleration parameter, energy density, pressure, cosmological constant and equation of state (EoS) in terms of redshift parameter and presented their dynamical behaviour graphically. In addition to Hubble parameter and deceleration parameter, the redshift variation of other higher order cosmographic parameters such as jerk, snap and lerk parameters has also been observed. The evolution of \((s,r)\) and \((q,r)\) trajectories has been examined to study different phases of the universe. Inspired by the study carried by Magana et al. (Mon. Not. R. Astron. Soc. 476(1), 1036, 2018), which consists of updated compilation of 51 points of homogenized and model-independent observational Hubble data, we have decided to use the same data for proposed study related with the expansion of the universe. Using these 51 values of observed Hubble measurements and performing \(\chi^{2}\) test, we have found the best suitable value of model parameter \(\beta\) and \(H_{0}\) (present value of Hubble parameter). The authors have noted that the obtained outcomes coincide with the modern cosmological observational data.



中文翻译:

可变减速参数的Sáez-Ballester理论中的Bianchi I型宇宙学模型

本研究是在Sáez-Ballester重力理论中采用可变减速参数研究Bianchi I型宇宙学模型的结果。在这里,我们还考虑了可变宇宙学常数\(\ Lambda \),这可能是讨论暗能量的候选者。使用可变减速参数即\(q = -1 + \ beta H \)(其中\(\ beta \)为正常数和\(H \)(哈勃参数)(Tiwari等人,Eur。Phys。J. Plus 132:1–9,2017),以及宇宙常数的可变形式的适当假设。我们已经根据红移参数表达了诸如哈勃参数,减速度参数,能量密度,压力,宇宙常数和状态方程(EoS)之类的宇宙学参数,并以图形方式展示了它们的动力学行为。除了哈勃参数和减速度参数外,还观察到其他更高阶的宇宙照相参数(例如加加速度,拍击和文员参数)的红移变化。\((s,r)\)\((q,r)\)的演变已经研究了轨道,以研究宇宙的不同阶段。受到Magana等人进行的研究的启发。(Mon.Not.R.Astron.Soc.476(1),1036,2018),它由51个均质且独立于模型的观测哈勃数据的更新汇编组成,我们决定将相同数据用于拟议的研究与宇宙膨胀有关。使用观察到的51个哈勃测量值并执行\(\ chi ^ {2} \)测试,我们找到了模型参数\(\ beta \)\(H_ {0} \)的最合适值(现值)的参数)。作者注意到,获得的结果与现代宇宙学观测数据相吻合。

更新日期:2021-05-24
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