Why do cosmological perturbations look classical to us? Export

@article{citeulike:3365527, abstract = {According to the inflationary scenario of cosmology, all structure in the Universe can be traced back to primordial fluctuations during an accelerated (inflationary) phase of the very early Universe. A conceptual problem arises due to the fact that the primordial fluctuations are quantum, while the standard scenario of structure formation deals with classical fluctuations. In this essay we present a concise summary of the physics describing the quantum-to-classical transition. We first discuss the observational indistinguishability between classical and quantum correlation functions in the closed system approach (pragmatic view). We then present the open system approach with environment-induced decoherence. We finally discuss the question of the fluctuations' entropy for which, in principle, the concrete mechanism leading to decoherence possesses observational relevance.}, archivePrefix = {arXiv}, author = {Kiefer, Claus and Polarski, David}, citeulike-article-id = {3365527}, citeulike-linkout-0 = {http://arxiv.org/abs/0810.0087}, citeulike-linkout-1 = {http://arxiv.org/pdf/0810.0087}, day = {1}, eprint = {0810.0087}, keywords = {coherence, cosmology, perturbations}, month = {Oct}, posted-at = {2008-10-02 09:05:22}, priority = {2}, title = {Why do cosmological perturbations look classical to us?}, url = {http://arxiv.org/abs/0810.0087}, year = {2008} }

TY - JOUR ID - citeulike:3365527 L3 - citeulike-article-id:3365527 N2 - According to the inflationary scenario of cosmology, all structure in the Universe can be traced back to primordial fluctuations during an accelerated (inflationary) phase of the very early Universe. A conceptual problem arises due to the fact that the primordial fluctuations are quantum, while the standard scenario of structure formation deals with classical fluctuations. In this essay we present a concise summary of the physics describing the quantum-to-classical transition. We first discuss the observational indistinguishability between classical and quantum correlation functions in the closed system approach (pragmatic view). We then present the open system approach with environment-induced decoherence. We finally discuss the question of the fluctuations' entropy for which, in principle, the concrete mechanism leading to decoherence possesses observational relevance. TI - Why do cosmological perturbations look classical to us? KW - coherence KW - cosmology KW - perturbations AU - Kiefer, Claus AU - Polarski, David PY - 2008/Oct/01/ UR - http://arxiv.org/abs/0810.0087 ER -