Cooling-heating properties of the FRW universe in gravity with a generalized conformal scalar field

IF 2.5 3区物理与天体物理 Q2 PHYSICS, PARTICLES & FIELDS

Nuclear Physics B Pub Date : 2024-10-17 DOI:10.1016/j.nuclphysb.2024.116719

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引用次数: 0

Abstract

In this paper, within the framework of modified gravity involving a conformal scalar field, we investigate the Joule-Thomson expansion of the Friedmann-Robertson-Walker (FRW) universe to identify cooling and heating regions. We observe a divergence in the Joule-Thomson coefficient (μ), precisely at the apparent horizon (

R_{A} = \sqrt{- 2 α}

) of the FRW universe, under conditions of negative gravitational coupling (

α < 0

), which aligns with a thermodynamic singularity. Furthermore, we determine the inversion temperature and pressure for the FRW universe, and elucidate the salient features of inversion and isenthalpic curves in the temperature-pressure (T-P) plane. We compare these findings with results obtained under Einstein gravity, discussing the influence of the modification term on the cooling and heating properties of the FRW universe. This work presents insights into the formation of cooling and heating regions within the FRW universe, contributing to a deeper understanding of the physical mechanisms behind cosmic expansion history.

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具有广义共形标量场的引力中 FRW 宇宙的冷却-加热特性

本文在涉及共形标量场的修正引力框架内，研究了弗里德曼-罗伯逊-沃克（FRW）宇宙的焦耳-汤姆森膨胀，以确定冷却和加热区域。我们观察到，在负引力耦合（α<0）条件下，焦耳-汤姆森系数（μ）在弗里德曼-罗伯逊-沃克宇宙的视平线（RA=-2α）处出现发散，这与热力学奇点一致。此外，我们还确定了 FRW 宇宙的反转温度和压力，并阐明了温度-压力（T-P）平面上反转曲线和等温线的显著特征。我们将这些发现与在爱因斯坦引力下获得的结果进行了比较，讨论了修正项对 FRW 宇宙冷却和加热特性的影响。这项工作提出了关于 FRW 宇宙中冷却和加热区域形成的见解，有助于加深对宇宙膨胀历史背后物理机制的理解。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Nuclear Physics B 物理-物理：粒子与场物理

CiteScore

5.50

自引率

7.10%

发文量

302

审稿时长

1 months

期刊介绍： Nuclear Physics B focuses on the domain of high energy physics, quantum field theory, statistical systems, and mathematical physics, and includes four main sections: high energy physics - phenomenology, high energy physics - theory, high energy physics - experiment, and quantum field theory, statistical systems, and mathematical physics. The emphasis is on original research papers (Frontiers Articles or Full Length Articles), but Review Articles are also welcome.