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引用次数: 0
摘要
在本文中,我们提出了对早期宇宙的曼苏里-诺扎里(Mansouri-Nozari)签名变化方法的重新解释,即在欧几里得体系中,度量签名只发生在 t 0 时。我们的研究结果表明,即使我们采用文献中常用的条件,能动张量在签名变化面上也不会消失。此外,我们在签名变化的框架内提出了一种修正的宇宙学,并讨论了我们的方法对宇宙学方程的修正。我们建立了状态方程参数及其奇异部分的约束条件,并确定了红移函数的有效状态方程。最后,我们证明在修正的ΛCDM模型中物质守恒定律仍然有效。
New insights on the signature change via the Colombeau framework
In this paper we propose a reinterpretation of the Mansouri–Nozari signature-change approach to the early Universe, in which the metric signature only occurs for t < 0 within the Euclidean regime, posing a challenge in providing coherent physical interpretations in advance. We ensure that the sign change occurs for t > 0 in the Euclidean regime. Our findings show that the energy-momentum tensor does not vanish on the signature-changing surface, even when we adopt conditions commonly used in the literature. Furthermore, we formulate a modified cosmology within the framework of signature-changing and discuss the modifications that our approach introduces to the cosmological equations. We establish a constraint relating the equation of state parameter and its singular part and we determine an effective equation of state as function of the redshift. Finally, we show that the law of conservation of matter in the modified ΛCDM model remains valid.
期刊介绍:
Classical and Quantum Gravity is an established journal for physicists, mathematicians and cosmologists in the fields of gravitation and the theory of spacetime. The journal is now the acknowledged world leader in classical relativity and all areas of quantum gravity.