论文标题
宇宙学的相互作用速率：重粒子和散射
Interaction rates in cosmology: heavy particle production and scattering
论文作者
论文摘要
我们研究了以空间平坦辐射为主的宇宙学中第一原理的过渡速率和横截面。我们考虑了标量颗粒的模型，以研究对成对歼灭的散射和重粒子产生，得出更一般的结论。 S-Matrix配方不适合在迅速扩展的宇宙学中研究这些无处不在的过程。我们引入了一种出于物理动机的绝热膨胀，该扩展依赖于在给定时间比粒子范围小得多的波长。该扩展中的领先顺序主导了过渡速率和横截面。几个重要的总体结果是宇宙学红移和有限的粒子地平线的直接后果：i）违反本地洛伦兹不变性的侵犯，ii）在有限的时间冻结生产横截面，iii）亚阈值产生重的颗粒，这是对有限粒子的局部能量的不确定性的结果。如果通过歼灭较轻的物种产生沉重的暗物质，则亚阈值产量会增强丰度。我们讨论这些影响的几种可能后果。
We study transition rates and cross sections from first principles in a spatially flat radiation dominated cosmology. We consider a model of scalar particles to study scattering and heavy particle production from pair annihilation, drawing more general conclusions. The S-matrix formulation is ill suited to study these ubiquitous processes in a rapidly expanding cosmology. We introduce a physically motivated adiabatic expansion that relies on wavelengths much smaller than the particle horizon at a given time. The leading order in this expansion dominates the transition rates and cross sections. Several important and general results are direct consequences of the cosmological redshift and a finite particle horizon: i) a violation of local Lorentz invariance, ii) freeze-out of the production cross section at a finite time, iii) sub-threshold production of heavier particles as a consequence of the uncertainty in the local energy from a finite particle horizon, a manifestation of the \emph{antizeno} effect. If heavy dark matter is produced via annihilation of a lighter species, sub-threshold production yields an enhanced abundance. We discuss several possible consequences of these effects.
