The Nature of Primordial Fluctuations from Anisotropic Inflation
| Autor: | Masa Aki Watanabe, Jiro Soda, Sugumi Kanno |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Inflation (cosmology)
Physics High Energy Physics - Theory Cosmology and Nongalactic Astrophysics (astro-ph.CO) Physics and Astronomy (miscellaneous) Primordial fluctuations Gravitational wave FOS: Physical sciences General Relativity and Quantum Cosmology (gr-qc) Inflaton Curvature General Relativity and Quantum Cosmology Metric expansion of space High Energy Physics - Phenomenology High Energy Physics - Phenomenology (hep-ph) Classical mechanics High Energy Physics - Theory (hep-th) Vector field Anisotropy Astrophysics - Cosmology and Nongalactic Astrophysics |
| Popis: | We study the statistical nature of primordial fluctuations from an anisotropic inflation which is realized by a vector field coupled to an inflaton. We find a suitable gauge, which we call the canonical gauge, for anisotropic inflation by generalizing the flat slicing gauge in conventional isotropic inflation. Using the canonical gauge, we reveal the structure of the couplings between curvature perturbations, vector waves, and gravitational waves. We identify two sources of anisotropy, i.e. the anisotropy due to the anisotropic expansion of the universe and that due to the anisotropic couplings among variables. It turns out that the latter effect is dominant. Since the coupling between the curvature perturbations and vector waves is the strongest one, the statistical anisotropy in the curvature perturbations is larger than that in gravitational waves. We find the cross correlation between the curvature perturbations and gravitational waves which never occurs in conventional inflation. We also find the linear polarization of gravitational waves. Finally, we discuss cosmological implication of our results. 20 pages, 4 figures;(V2) a reference added |
| Databáze: | OpenAIRE |
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