Cosmological perturbations from varying masses and couplings
Cosmological perturbations from varying masses and couplings
复制标题
来自不同质量和耦合的宇宙扰动
DOI：
10.1103/physrevd.69.083526
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发表时间：
2003
影响因子：
5
通讯作者：
F. Vernizzi
中科院分区：
文献类型：
--
作者：
F. Vernizzi
我们研究了一个大质量粒子物种的质量和衰变率被允许依赖于光标量场的期望值的统治和衰变过程中的扰动的演变。我们专注于光场是缓慢滚动的情况下，表明在一个阶段的不均匀质量的统治和衰减的光场的isocurvature扰动转换成曲率扰动的效率是9倍大于当质量是固定的。我们推导出一个条件的湮灭截面和衰变率的大质量粒子的统治，我们表明，标准模型粒子不能主宰宇宙核合成之前。我们还比较了这种机制与曲率模型。最后，观察签名进行了讨论。如果暗物质是由暴胀子和大质量粒子衰变产生的，那么就可以产生冷暗物质等曲率模式。存在非高斯性：它们是卡方偏差。然而，它们可能太小而无法观察到。
We study the evolution of perturbations during the domination and decay of a massive particle species whose mass and decay rate are allowed to depend on the expectation value of a light scalar field. We specialize in the case where the light field is slow rolling, showing that during a phase of inhomogeneous mass domination and decay the isocurvature perturbation of the light field is converted into a curvature perturbation with an efficiency which is nine times larger than when the mass is fixed. We derive a condition on the annihilation cross section and on the decay rate for the domination of the massive particles and we show that standard model particles cannot dominate the universe before nucleosynthesis. We also compare this mechanism with the curvaton model. Finally, observational signatures are discussed. A cold dark matter isocurvature mode can be generated if the dark matter is produced out of equilibrium by both the inflaton and the massive particle species decay. Non-Gaussianities are present: they are chi-square deviations. However, they might be too small to be observable.