Rajdeep Mazumdar, Mrinnoy M. Gohain, Kalyan Bhuyan
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引用次数: 0
摘要
在这项工作中,我们研究了在广义相对论(GR)框架下,加入粘性流体如何导致精确的反弹宇宙学解。具体地说,我们提出了一种新颖的体粘性系数参数化形式:$\zeta = \zeta_0 (t-t_0)^{-2n} H$ ,其中$\zeta_0$, $n$是一些正常数。H$,其中$\zeta_0$、$n$为一些正常数,$t_0$为反弹纪元。我们通过研究各种能量条件和其他相关宇宙学观测指标,以及模型参数如何影响宇宙演化,来探讨这种体粘度形式如何有助于解释早期宇宙的行为,特别是非乒呤反弹情景。我们证明了在反弹点会发生 NEC 和 SEC 违反,而 DEC 满足。最后,我们基于哈勃参数的线性阶扰动进行了稳定性检验。我们发现,扰动在后期会逐渐消失,这表明反弹情景的行为是稳定的。
Cosmological Bounce Scenario with a Novel Parametrization of Bulk Viscosity
In this work, we have studied how incorporating viscous fluids leads to exact bounce cosmological solutions in general relativity (GR) framework. Specifically, we propose a novel parameterization of bulk viscosity coefficient of the form $\zeta = \zeta_0 (t-t_0)^{-2n} H$, where $\zeta_0$, $n$ being some positive constants and $t_0$ is the bounce epoch. We investigate how this form of bulk viscosity may assist in explaining the early universe's behaviour, with a particular focus on non-singular bounce scenario by studying the various energy conditions and other related cosmological observables and how the model parameters affect the evolution of the Universe. We demonstrate that the NEC and SEC violation occurs at the bounce point while DEC is satisfied. Finally, we carried out a stability check based on linear order perturbation to the Hubble parameter. We found that the perturbation vanishes asymptotically at later times, which indicates a stable behaviour of the bounce scenario
期刊介绍:
ACS Applied Bio Materials is an interdisciplinary journal publishing original research covering all aspects of biomaterials and biointerfaces including and beyond the traditional biosensing, biomedical and therapeutic applications.
The journal is devoted to reports of new and original experimental and theoretical research of an applied nature that integrates knowledge in the areas of materials, engineering, physics, bioscience, and chemistry into important bio applications. The journal is specifically interested in work that addresses the relationship between structure and function and assesses the stability and degradation of materials under relevant environmental and biological conditions.