Local minima of the potential can be metastable up to cosmologically long times thanks to energy conservation. We explore the possibility that theories with negative kinetic energy (ghosts) can be metastable up to cosmologically long times. In classical mechanics, ghosts undergo spontaneous lockdown rather than run away if weakly coupled and nonresonant. Physical examples of this phenomenon are shown. In quantum mechanics, this leads to metastability similar to vacuum decay. In classical field theory, lockdown is broken by resonances and ghosts behave statistically, drifting toward infinite entropy as no thermal equilibrium exists. We analytically and numerically compute the runaway rate finding that it is cosmologically slow in four-derivative gravity, where ghosts have gravitational interactions only. In quantum field theory, the ghost runaway rate is naively infinite in perturbation theory, analogously to what is found in early attempts to compute vacuum tunnelling; we do not know the true rate.

中文翻译：

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负动能是否亚稳态？

由于能量守恒，势能的局部最小值可以在宇宙学上长时间保持亚稳态。我们探索了具有负动能（鬼）的理论可以在宇宙学上长时间保持亚稳态的可能性。在经典力学中，如果弱耦合和非共振，鬼会自发地锁定而不是逃跑。显示了这种现象的物理示例。在量子力学中，这会导致类似于真空衰变的亚稳态。在经典场论中，由于不存在热平衡，锁定会被共振打破，而鬼魂的行为在统计上会朝着无穷大的熵方向漂移。我们通过分析和数值计算了失控率，发现在四导数引力中它在宇宙学上是缓慢的，其中鬼只有引力相互作用。在量子场论中，在扰动理论中，鬼逃逸率是无限的，类似于早期尝试计算真空隧道时发现的情况；我们不知道真实汇率。