Pointer states for primordial fluctuations in inflationary cosmology
Pointer states for primordial fluctuations in inflationary cosmology
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DOI：
10.1088/0264-9381/24/7/002
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发表时间：
2006-10
影响因子：
3.5
通讯作者：
C. Kiefer;I. Lohmar;D. Polarski;A. Starobinsky
中科院分区：
文献类型：
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作者：
C. Kiefer;I. Lohmar;D. Polarski;A. Starobinsky
暴胀宇宙学中的原始涨落在波长大于哈勃尺度时通过退相干获得经典性质。虽然退相干是有效的，但它并不完全，因此原始相关性的很大一部分仍然保留到现在。我们解决的指针状态，提供了一个经典的基础上的波动相对于环境（其他领域）的影响的问题。应用方法从量子理论的开放系统（Lindblad方程），我们表明，这个基础是由窄高斯近似本征态的字段振幅。我们计算了涨落的冯诺依曼熵和线性熵。它们与每个场模式的最大熵的比率定义了熵意义上的部分退相干的程度。我们还确定了部分退相干的时间，使魏格纳函数积极无处不在，在通货膨胀期间的超级哈勃模式，几乎是独立的耦合到环境中，只是略大于哈勃时间。另一方面，假设一个代表性的环境（光子浴），子哈勃模式的退相干时间是有限的，只有当一些真实的耗散存在。
Primordial fluctuations in inflationary cosmology acquire classical properties through decoherence when their wavelengths become larger than the Hubble scale. Although decoherence is effective, it is not complete, so a significant part of primordial correlations remains up to the present moment. We address the issue of the pointer states which provide a classical basis for the fluctuations with respect to the influence by an environment (other fields). Applying methods from the quantum theory of open systems (the Lindblad equation), we show that this basis is given by narrow Gaussians that approximate eigenstates of field amplitudes. We calculate both the von Neumann and linear entropy of the fluctuations. Their ratio to the maximal entropy per field mode defines a degree of partial decoherence in the entropy sense. We also determine the time of partial decoherence making the Wigner function positive everywhere which, for super-Hubble modes during inflation, is virtually independent of coupling to the environment and is only slightly larger than the Hubble time. On the other hand, assuming a representative environment (a photon bath), the decoherence time for sub-Hubble modes is finite only if some real dissipation exists.