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arXiv 2408.06176gr-qc
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关于Einstein-Hilbert作用的KG约束一般形变变换

On the KG-constrained general disformal transformation of the Einstein-Hilbert action

Allan L. Alinea, Joshwa DJ. Ordonez

AI总结:

本文研究了Einstein-Hilbert作用在一组三重KG约束下的一般形变变换,发现三个约束可显著简化变换后的作用,并给出了其在四维、三维和二维时空中的具体形式与不变性。

摘要:

尽管广义相对论在解释涉及宇宙或其部分的诸多现象与自然行为方面取得了巨大成功,但它远非一个完备的理论。聚焦于其在标量张量理论框架内的扩展,我们研究了Einstein-Hilbert作用在一组三重KG约束下的一般形变变换。其核心思想是,一般形变变换会导致极其复杂的作用,需要一组约束来驯制其最终形式。受以往关于无质量Klein-Gordon方程在一般形变变换下可逆性与不变性的研究启发,我们确定了三个约束,从而显著简化了变换后的Einstein-Hilbert作用。在四维时空中,我们发现变换后的作用是原始作用与一项形变贡献之和,该贡献包含一个六项Lagrangian,其中包括Ricci张量与标量场导数之和及动能项的耦合。在三维时空中,该形变贡献变为一个五项Lagrangian。最后,在二维时空中,Einstein-Hilbert作用在受约束的形变变换下保持不变。

英文摘要:

Although with great successes in explaining phenomena and natural behaviour involving the Universe or a part thereof, the General Theory of Relativity is far from a complete theory. Focusing on its extension within the framework of scalar tensor theory, we investigate the transformation of the Einstein-Hilbert action under the general disformal transformation coupled with a set of triple KG constraints. The idea is that the general disformal transformation leads to an extremely complicated action necessitating a set of constraints to tame the resulting form. Motivated by previous studies on the invertibility and invariance of the massless Klein-Gordon equation under the general disformal transformation, we identify three constraints that significantly simplifies the transformed Einstein-Hilbert action. In four spacetime dimensions, we find that the transformed action is a sum of the original action and a disformal contribution involving a six-term Lagrangian that includes the Ricci tensor coupled to a sum of derivatives of scalar fields and kinetic terms. In three spacetime dimensions, the disformal contribution becomes a five-term Lagrangian. Lastly, in two spacetime dimensions, the Einstein-Hilbert action is invariant under the constrained disformal transformation.

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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