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arXiv 2402.17422gr-qcastro-ph.CO
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TDiff标量场的对称性恢复

Symmetry restoration for TDiff scalar fields

Darío Jaramillo-Garrido, Antonio L. Maroto, Prado Martín-Moruno

AI总结:

本文通过引入附加矢量场恢复TDiff标量场的完全微分同胚对称性,分析了势主导与动能主导区间的动力学行为,并推导了非绝热完美流体的有效声速表达式及耦合函数的物理条件。

摘要:

我们探讨了通过引入附加场在仅具有横向微分同胚(TDiff)不变性的理论中恢复完全微分同胚(Diff)不变性的想法。特别地,我们详细考虑了TDiff不变标量场的情况,以及如何通过引入附加矢量场在保持局域性的前提下恢复Diff对称性。我们从协变化的作用量重新获得了相应的动力学和能量-动量张量,并分析了势主导和动能主导的区间。对于前者,该理论描述了宇宙学常数类型的行为;而对于后者,我们证明了该理论可以描述一种绝热完美流体,其状态方程和声速可以以直接的方式获得。此外,具有完全对称性的重新表述使我们能够分析超越这些特定区间的理论引力性质。特别地,我们找到了非绝热完美流体的有效声速的一般表达式,这为我们提供了耦合函数应满足的物理上合理的条件。最后,我们研究了导致绝热流体的特定模型。

英文摘要:

We explore the idea of restoring the full diffeomorphism (Diff) invariance in theories with only transverse diffeomorphisms (TDiff) by the introduction of additional fields. In particular, we consider in detail the case of a TDiff invariant scalar field and how Diff symmetry can be restored preserving locality by introducing an additional vector field. We reobtain the corresponding dynamics and energy-momentum tensor from the covariantized action and analyze the potential and kinetic domination regimes. For the former, the theory describes a cosmological constant-type behaviour, while for the latter we show that the theory can describe an adiabatic perfect fluid whose equation of state and speed of sound is obtained in a straightforward way. Furthermore, the reformulation with the full symmetry allows us to analyze the gravitational properties of the theory beyond those particular regimes. In particular, we find the general expression for the effective speed of sound of the non-adiabatic perfect fluid, which provides us with physically reasonable conditions that should be satisfied by the coupling functions. Finally, we investigate the particular models leading to an adiabatic fluid.

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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