English

Does Anisotropic "Inflation" Produce a Small Statistical Anisotropy?

Cosmology and Nongalactic Astrophysics 2018-02-14 v1 General Relativity and Quantum Cosmology High Energy Physics - Phenomenology High Energy Physics - Theory

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 gg_*. 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 g102g_*\le 10^{-2} with a high probability about 99.999%99.999\%.

Keywords

Cite

@article{arxiv.1711.11539,
  title  = {Does Anisotropic "Inflation" Produce a Small Statistical Anisotropy?},
  author = {Tomohiro Fujita and Ippei Obata},
  journal= {arXiv preprint arXiv:1711.11539},
  year   = {2018}
}
R2 v1 2026-06-22T23:02:44.469Z