We review (and extend) the analysis of general theories of all interactions (gravity included) where the mass scales are due to dimensional transmutation. Quantum consistency requires the presence of terms in the action with four derivatives of the metric. It is shown, nevertheless, how unitary is achieved and the classical Ostrogradsky instabilities can be avoided. The four-derivative terms also allow us to have a UV complete framework and a naturally small ratio between the Higgs mass and the Planck scale. Moreover, black holes of Einstein gravity with horizons smaller than a certain (microscopic) scale are replaced by horizonless ultracompact objects that are free from any singularity and have interesting phenomenological applications. We also discuss the predictions that can be compared with observations of the microwave background radiation anisotropies and find that this scenario is viable and can be tested with future data. Finally, how strong phase transitions can emerge in models of this type with approximate scale symmetry and how to test them with GW detectors is reviewed and explained.

中文翻译：

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引力和宇宙学中的维度嬗变

我们回顾（并扩展）对所有相互作用（包括重力）的一般理论的分析，其中质量尺度是由维度嬗变引起的。量子一致性要求在动作中存在具有度量的四个导数的项。然而，它显示了如何实现酉并可以避免经典的 Ostrogradsky 不稳定性。四导数还允许我们拥有一个完整的 UV 框架，以及希格斯质量和普朗克尺度之间的自然小比例。此外，视界小于某个（微观）尺度的爱因斯坦引力黑洞被无视界的超致密天体所取代，这些天体没有任何奇点，并且具有有趣的现象学应用。我们还讨论了可以与微波背景辐射各向异性观察进行比较的预测，并发现这种情况是可行的，可以用未来的数据进行测试。最后，回顾和解释了在具有近似尺度对称性的此类模型中会出现多强的相变以及如何使用 GW 探测器对其进行测试。