非黎曼几何中的弹跳宇宙学分析

IF 1.9 4区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS
M. Sharif, M. Zeeshan Gul, Nusrat Fatima
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引用次数: 0

摘要

本手稿的主要目的是研究 f(Q) 引力背景下的反弹宇宙学,其中 Q 定义了非度量性。为此,我们使用了重构方法,并考虑了具有完美物质构型的平坦弗里德曼-罗伯逊-沃克时空。我们利用尺度因子的时间导数,即ȧ<0、ȧ=0 和ȧ>0 分别给出收缩、反弹点和膨胀阶段,来研究第一收缩阶段如何给出膨胀阶段。此外,由于存在额外的非线性表达式,求解修正场方程非常困难,因此我们采用了阶次削减法。分析表明,在所需的反弹条件下,宇宙的原始奇异性会减弱。我们的结论是,加速发生在反弹点附近,所考虑的 f(Q) 模型与当前的宇宙加速膨胀是一致的。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
Analysis of bouncing cosmology in non-Riemannian geometry

The main objective of this manuscript is to investigate the bouncing cosmology in the background of f(Q) gravity, where Q defines the non-metricity. For this purpose, we use the reconstruction approach and consider a flat Friedmann–Robertson–Walker spacetime with perfect matter configuration. We examine how the first contracting phase gives the expansion by using a temporal derivative of the scale factor, i.e., ȧ<0, ȧ=0 and ȧ>0 give contraction, bounce point and expansion phases, respectively. Further, we use the order reduction method to solve the modified field equations as these are very difficult due to the presence of additional non-linear expressions. It is analyzed that the original singularity of the universe diminishes for the required bounce conditions. We conclude that the acceleration occurs near the bouncing point and the considered f(Q) models are consistent with the current cosmic accelerated expansion.

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来源期刊
New Astronomy
New Astronomy 地学天文-天文与天体物理
CiteScore
4.00
自引率
10.00%
发文量
109
审稿时长
13.6 weeks
期刊介绍: New Astronomy publishes articles in all fields of astronomy and astrophysics, with a particular focus on computational astronomy: mathematical and astronomy techniques and methodology, simulations, modelling and numerical results and computational techniques in instrumentation. New Astronomy includes full length research articles and review articles. The journal covers solar, stellar, galactic and extragalactic astronomy and astrophysics. It reports on original research in all wavelength bands, ranging from radio to gamma-ray.
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