Linear versus nonlinear relaxation: Consequences for reheating and thermalization.
Linear versus nonlinear relaxation: Consequences for reheating and thermalization.
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DOI：
10.1103/physrevd.52.6805
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发表时间：
1995-12
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影响因子：
--
通讯作者：
Boyanovsky;D'Attanasio;de Vega HJ;Holman;Lee
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文献类型：
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作者：
Boyanovsky;D'Attanasio;de Vega HJ;Holman;Lee
我们考虑标量场的情况，膨胀子，耦合到轻标量和费米子，并研究了在线性和非线性两种情况下通过粒子产生的膨胀子的弛豫。这对暴胀宇宙模型中的再加热问题有直接的应用。线性状态分析为再热问题的标准方法提供了一个基本原理，但是我们要区分弛豫和热化。我们发现，当暴胀开始于{重要的非线性}区域时，粒子的产生通常是一种比单粒子衰变更有效的将能量从暴胀零模式转移到更轻的标量量子的方式。对于非线性系统，我们自洽地考虑了膨胀场期望值的演化与量子涨落的演化耦合。对重整方程的详尽数值分析表明，产生的颗粒的分布远离热分布，并表现出与开放通道相关的影响。在费米子的情况下，泡利阻塞在暴胀演化的早期就开始阻碍能量向费米子模式的转移。我们讨论了热化问题，并进一步估计了再加热温度与膨胀质量成正比。特别讨论了Polonyi问题的宇宙学含义。{版权所有}1995美国物理学会。«少
We consider the case of a scalar field, the inflaton, coupled to both lighter scalars and fermions, and study the relaxation of the inflaton via particle production in both the linear and nonlinear regimes. This has an immediate appilcation to the reheating problem in inflationary universe models. The linear regime analysis offers a rationale for the standard approach to the reheating problem, but we make a distinction between relaxation and thermalization. We find that particle production when the inflaton starts in the {ital nonlinear} region is typically a far more efficient way of transferring energy out of the inflaton zero mode and into the quanta of the lighter scalar than single particle decay. For the nonlinear regime we takn into account self-consistently the evolution of the expectation value of the inflaton field coupled to the evolution of the quantum fluctuations. An exhaustive numerical analysis of the renormalized equations reveals that the distribution of produced particles is far from thermal, and exhibits the effect associated with open channels. In the fermionic case, Pauli blocking begins to hinder the transfer of energy into the fermion modes very early on in the evolution of the inflaton. We discuss the issue of thermalization andmore » estimate the reheating temperature to be proportional to the inflaton mass. Cosmological implications are discussed in particular for the Polonyi problem. {copyright} 1995 The American Physical Society.« less