1. Constraining the Anisotropic Expansion of Universe
- Author
-
Zhong-Liang Tuo, Yin-Zhe Ma, Rong-Gen Cai, and Bo Tang
- Subjects
High Energy Astrophysical Phenomena (astro-ph.HE) ,Physics ,Nuclear and High Energy Physics ,Cosmology and Nongalactic Astrophysics (astro-ph.CO) ,Field (physics) ,media_common.quotation_subject ,FOS: Physical sciences ,Astrophysics ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Cosmology ,Universe ,Metric expansion of space ,Observational cosmology ,Dark energy ,Peculiar velocity ,Anisotropy ,Astrophysics - High Energy Astrophysical Phenomena ,media_common ,Astrophysics - Cosmology and Nongalactic Astrophysics - Abstract
We study the possibly existing anisotropy in the accelerating expansion universe with the Union2 Type Ia supernovae data and Gamma-ray burst data. We construct a direction-dependent dark energy model and constrain the anisotropy direction and strength of modulation. We find that the maximum anisotropic deviation direction is $(l,\,b)=(126^{\circ},\,13^{\circ})$ (or equivalently $(l,\,b)=(306^{\circ},\,-13^{\circ})$), and the current anisotropy level is $g_0=0.030_{+0.010}^{-0.030}$ ($1\sigma$ confidence level with Union2 data). Our results do not show strong evidence for the anisotropic dark energy model. We also discuss potential methods that may distinguish the peculiar velocity field from the anisotropic dark energy model., Comment: 9 pages,3 figures,8 tables
- Published
- 2013