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arXiv · 1711.11539

Does Anisotropic "Inflation" Produce a Small Statistical Anisotropy?

Tomohiro Fujita·Ippei Obata
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Abstract

Anisotropic inflation is an interesting model with an U(1) gauge field and it predicts the statistical anisotropy of the curvature perturbation characterized by a parameter $g_*$. However, we find that the background gauge field does not follow the classical attractor solution due to the stochastic effect. We develop the stochastic formalism of a vector field and solve Langevin and Fokker-Planck equations. It is shown that this model is excluded by the CMB constraint $g_*\le 10^{-2}$ with a high probability about $99.999\%$.

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Tomohiro Fujita, Ippei Obata. 2017-11-30. Does Anisotropic "Inflation" Produce a Small Statistical Anisotropy?. https://doi.org/10.1088/1475-7516%2F2018%2F01%2F049

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