Double polytropic cosmic acceleration from the Murnaghan equation of state
arxiv(2024)
摘要
We consider a double polytropic cosmological fluid and demonstrate that, when
one constituent resembles a bare cosmological constant while the other emulates
a generalized Chaplygin gas, a good description of the Universe's large-scale
dynamics is obtained. In particular, our double polytropic reduces to the
Murnaghan equation of state, whose applications are already well established in
solid state physics and classical thermodynamics. Intriguingly, our model
approximates the conventional ΛCDM paradigm while reproducing the
collective effects of logotropic and generalized Chaplygin fluids across
different regimes. To check the goodness of our fluid description, we analyze
first order density perturbations, refining our model through various orders of
approximation, utilizing σ_8 data alongside other cosmological data
sets. Encouraging results suggest that our model, based on the Murnaghan
equation of state, outperforms the standard cosmological background within
specific approximate regimes and, on the whole, surpasses the standard
phenomenological reconstruction of dark energy.
更多查看译文
AI 理解论文
溯源树
样例
生成溯源树,研究论文发展脉络
Chat Paper
正在生成论文摘要