论文标题
量子重力中的因果关系，单位性和稳定性：非扰动的视角
Causality, unitarity and stability in quantum gravity: a non-perturbative perspective
论文作者
论文摘要
预期在重力路径积分水平上的重新量量子波动将导致非本地有效作用，从而导致传播器的非平凡动量依赖性。 （穿着的）重力传播器必须满足哪些属性以及是否可以满足它们是关键的开放问题。在这项工作中，我们介绍了重力传播剂的动量依赖性的标准和条件，该繁殖物与单位性，因果关系和在非扰动环境中的稳定性一致。为此，我们重新审视了这些条件的几个方面，突出了一些在最近的讨论中丢失的警告和微妙之处，并阐明了其他问题，据我们所知，尚未详细研究。我们讨论了这些概念对重力传播器的性质的后果。最后，我们提供了满足单位性和因果关系的繁殖者的例子，同时避免了速旋和真空不稳定性，并允许进行分析芯旋转。
Resumming quantum fluctuations at the level of the gravitational path integral is expected to result in non-local effective actions and thus in a non-trivial momentum dependence of the propagator. Which properties the (dressed) graviton propagator has to satisfy and whether they can all be met are key open questions. In this work we present criteria and conditions for the momentum dependence of a graviton propagator which is consistent with unitarity, causality, and stability in a non-perturbative setting. To this end, we revisit several aspects of these conditions, highlighting some caveats and subtleties that got lost in recent discussions, and spelling out others that to our best knowledge have not been studied in detail. We discuss the consequences of these concepts for the properties of the graviton propagator. Finally, we provide examples of propagators satisfying unitarity and causality, while avoiding tachyonic and vacuum instabilities, and allowing for an analytic Wick rotation.
