论文标题
宇宙跨普兰克的猜想无效
Cosmological Trans-Planckian Conjectures are not Effective
论文作者
论文摘要
值得注意的是,CMB揭示的原始波动与如果量子波动通过加速宇宙膨胀在天空中延伸到天空时,量子的波动会是什么样。已经观察到,同样的拉伸也带来很小的(甚至是跨普兰克)长度缩放到可观察到的大小,如果将其推断到过去足够远。这可能会危害后来对后期宇宙学的描述,通过将不受控制的跨普兰克理论错误引入所有计算中。最近已经开发了最近的猜测,例如Trans-Planckian审查制度猜想(TCC),以避免此问题。我们重新审视了旧论点,为什么(控制和控制)有效的现场理论(EFT)管理延迟宇宙学的一致性不一定受到由于普遍扩张而导致的模式下降的威胁,即使EFT方法可能在很早的时候破裂。 EFT方法的失败仅在早期预测依赖于这些早期的非绝热行为时会带来问题(例如,对于弹跳宇宙学通常是正确的)。我们使用简单的非重力示例(例如缓慢滚动的标量场)以及在缓慢变化的磁场中为带电颗粒的兰道水平之间的间距说明了我们的论点,因为这些磁场会出现类似的问题,并且更易于理解。我们对与紫外线完成相关的问题发表评论。我们的论点不必使TCC之类的投机思想无效,但建议当前证据不需要它们。
It is remarkable that the primordial fluctuations as revealed by the CMB coincide with what quantum fluctuations would look like if they were stretched across the sky by accelerated cosmic expansion. It has been observed that this same stretching also brings very small -- even trans-Planckian -- length scales up to observable sizes if extrapolated far enough into the past. This potentially jeopardizes later descriptions of late-time cosmology by introducing uncontrolled trans-Planckian theoretical errors into all calculations. Recent speculations, such as the Trans-Planckian Censorship Conjecture (TCC), have been developed to avoid this problem. We revisit old arguments why the consistency of (and control over) the Effective Field Theory (EFT) governing late-time cosmology is not necessarily threatened by the descent of modes due to universal expansion, even if EFT methods may break down at much earlier times. Failure of EFT methods only poses a problem if late-time predictions rely on non-adiabatic behaviour at these early times (such as is often true for bouncing cosmologies, for example). We illustrate our arguments using simple non-gravitational examples such as slowly rolling scalar fields and the spacing between Landau levels for charged particles in slowly varying magnetic fields, for which similar issues arise and are easier to understand. We comment on issues associated with UV completions. Our arguments need not invalidate speculative ideas like the TCC but suggest they are not required by the present evidence.