Shift-symmetric Horndeski gravity in the asymptotic-safety paradigm
Shift-symmetric Horndeski gravity in the asymptotic-safety paradigm
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DOI：
10.1088/1475-7516/2023/02/052
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发表时间：
2022-12
影响因子：
6.4
通讯作者：
A. Eichhorn;Rafael R. Lino dos Santos;Fabian Wagner
中科院分区：
文献类型：
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作者：
A. Eichhorn;Rafael R. Lino dos Santos;Fabian Wagner
Horndeski引力是动力学暗能量的现象学模型的热门竞争者，因此受到观测约束。在这项工作中，我们问Horndeski引力是否可以不仅仅是一个现象学模型，而是成为一个基本理论，它延伸到高能量尺度，包括量子效应。我们发现，在渐近安全的范式，紫外线完成一类简单的模型Horndeski重力是可以实现的，但强烈的约束耦合的理论。这些约束与动力学暗能量不相容。此外，我们在有效场论方法中发现了类似的结果：在普朗克尺度以下没有新的强耦合物理的假设下，量子引力涨落迫使Horndeski耦合太小，无法解释动态暗能量。
Horndeski gravity is a popular contender for a phenomenological model of dynamical dark energy, and as such subject to observational constraints. In this work, we ask whether Horndeski gravity can be more than a phenomenological model and instead become a fundamental theory, which extends towards high energy scales and includes quantum effects. We find that within the asymptotic-safety paradigm, an ultraviolet completion of a simple class of models of Horndeski gravity is achievable, but places strong constraints on the couplings of the theory. These constraints are not compatible with dynamical dark energy. Further, we find a similar result in an effective-field theory approach to this class of models of Horndeski gravity: under the assumption that there is no new strongly-coupled physics below the Planck scale, quantum gravity fluctuations force the Horndeski couplings to be too small to achieve an explanation of dynamical dark energy.