Study of the spectrum of inflaton perturbations
Study of the spectrum of inflaton perturbations
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DOI：
10.1103/physrevd.80.063534
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发表时间：
2009-09-01
影响因子：
5
通讯作者：
Parker, Leonard
中科院分区：
文献类型：
--
作者：
Glenz, Matthew M.;Parker, Leonard
我们研究的频谱暴胀子波动造成的任何给定的长时期的指数膨胀。在我们的方法中，在所有模式上求和的暴胀子色散中的红外和紫外发散没有出现。我们展示了如何产生的扰动谱的尺度不变性。我们还研究了标量扰动的度量，是由暴胀子波动，已离开哈勃球在通货膨胀和频谱的密度扰动，他们在再入后，通货膨胀已经结束。当膨胀过程中的暴胀子色散谱重整化，我们表明（对于二次暴胀子潜在的情况下），密度扰动谱接近一个质量无关的限制作为暴胀子质量接近零，并保持在该极限值的质量小于约1/4的膨胀哈勃常数。我们表明，这种限制行为不会发生，如果一个人只使闵可夫斯基空间减法，没有进一步的绝热减法，涉及的时间导数的膨胀比例因子a（t）。我们还发现了一个参数化的表达所产生的能量密度的变化，在a（t）的通货膨胀结束。如果暴胀的结束足够突然，那么对应于这个能量密度的温度可能非常显著。我们还表明，暴胀开始前存在的暴胀子场的波动在暴胀过程中不会消散，今天可能有显着的观测效果。其机制是由来自真空的受激发射的初始波动引起的。
We examine the spectrum of inflaton fluctuations resulting from any given long period of exponential inflation. Infrared and ultraviolet divergences in the inflaton dispersion summed over all modes do not appear in our approach. We show how the scale invariance of the perturbation spectrum arises. We also examine the spectrum of scalar perturbations of the metric that is created by the inflaton fluctuations that have left the Hubble sphere during inflation and the spectrum of density perturbations that they produce at reentry after inflation has ended. When the inflaton dispersion spectrum is renormalized during the expansion, we show (for the case of the quadratic inflaton potential) that the density perturbation spectrum approaches a mass-independent limit as the inflaton mass approaches zero, and remains near that limiting value for masses less than about 1/4 of the inflationary Hubble constant. We show that this limiting behavior does not occur if one only makes the Minkowski space subtraction, without the further adiabatic subtractions that involve time derivatives of the expansion scale factor a(t). We also find a parametrized expression for the energy density produced by the change in a(t) as inflation ends. If the end of inflation were sufficiently abrupt, then the temperature corresponding to this energy density could be very significant. We also show that fluctuations of the inflaton field that are present before inflation starts are not dissipated during inflation and could have a significant observational effect today. The mechanism for this is caused by the initial fluctuations through stimulated emission from the vacuum.