标题： 各向异性“暴胀”会产生小的统计各向异性吗？ 显示英文标题

标题： Does Anisotropic "Inflation" Produce a Small Statistical Anisotropy?

摘要： 各向异性暴胀是一个有趣的模型，包含一个U(1)规范场，并且它预测了由参数$g_*$表征的曲率扰动的统计各向异性。 然而，我们发现由于随机效应，背景规范场并不遵循经典吸引子解。 我们发展了矢量场的随机形式并求解了朗之万方程和福克-普朗克方程。 结果显示，该模型被CMB约束$g_*\le 10^{-2}$排除，概率很高，约为$99.999\%$。 显示英文摘要

摘要： 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 $99.999\%$.