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arXiv 2410.04584gr-qcastro-ph.COhep-thphysics.comp-ph
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新标量张量引力理论中物质与几何的相互作用

Matter--Geometry interplay in new scalar tensor theories of gravity

Mihai Marciu

AI总结:

本文研究能量-动量张量与爱因斯坦张量直接耦合的标量张量引力中物质-几何的相互作用,通过开放系统不可逆热力学方法推导相关热力学量,在Roberson-Walker度规下求得渐近解,并结合观测数据约束哈勃率参数化形式,得到存在物质产生机制的宇宙学模型数值解。

摘要:

本文研究了能量-动量张量直接与爱因斯坦张量耦合的标量张量引力理论中物质与几何之间可能存在的相互作用。在得到$f(R, G_{μν}T^{μν})$引力的标量张量表示后,本文采用基于开放系统不可逆过程热力学的方法展开分析。通过该方式直接得到了多种热力学性质,例如物质产生(湮灭)率以及相应的产生(湮灭)压强。在Roberson-Walker度规的情形下,我们在渐近区域找到了若干解析解和数值解。在论文的最后部分,针对宇宙计时钟(CC)和重子声学振荡(BAO)观测数据,我们利用马尔可夫链蒙特卡罗算法对哈勃率的一种特定参数化形式进行了约束,得到了一个能够描述该宇宙学模型的近似数值解。对于该模型,我们通过微调得到了一些数值解,这些解在不同的特定区域展现出物质产生机制。

英文摘要:

The paper studies the possible interplay between matter and geometry in scalar tensor theories of gravitation where the energy--momentum tensor is directly coupled with the Einstein tensor. After obtaining the scalar tensor representation of the $f(R, G_{μν}T^{μν})$ gravity, the analysis continue with an approach based on the thermodynamics of irreversible processes in open systems. To this regard, various thermodynamic properties are directly obtained in this manner, like the matter creation (annihilation) rate and the corresponding creation (annihilation) pressure. In the case of the Roberson--Walker metric several analytic and numerical solutions are found in the asymptotic regime. In the last part of the manuscript a specific parametrization for the Hubble rate is constrained using the Markov Chain Monte Carlo algorithms in the case of cosmic chronometers (CC) and BAO observations, obtaining an approximate numerical solution which can describe the cosmological model. For this model, we have obtained by fine--tuning some numerical solutions which exhibit creation mechanisms in different specific regimes.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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