skip to main content

SciTech ConnectSciTech Connect

Title: Constraints on dark energy from new observations including Pan-STARRS

In this paper, we set the new limits on the equation of state parameter (EoS) of dark energy with the observations of cosmic microwave background radiation (CMB) from Planck satellite, the type Ia supernovae from Pan-STARRS and the baryon acoustic oscillation (BAO). We consider two parametrization forms of EoS: a constant w and time evolving w(a)=w{sub 0}+w{sub a}(1-a). The results show that with a constant EoS, w=-1.141±0.075 68% C.L.), which is consistent with ΛCDM at about 2σ confidence level. For a time evolving w(a) model, we get w{sub 0}=-1.09{sup +0.16}{sub -0.18} 1σ C.L.), w{sub a}=-0.34{sup +0.87}{sub -0.51} 1σ C.L.), and in this case ΛCDM can be comparable with our observational data at 1σ confidence level. In order to do the parametrization independent analysis, additionally we adopt the so called principal component analysis (PCA) method, in which we divide redshift range into several bins and assume w as a constant in each redshift bin (bin-w). In such bin-w scenario, we find that for most of the bins cosmological constant can be comparable with the data, however, there exists few bins which give w deviating from ΛCDM at more than 2σ confidence level, which shows a weak hint for the time evolvingmore » behavior of dark energy. To further confirm this hint, we need more data with higher precision.« less
Authors:
 [1] ;  [2] ; ;  [3] ;  [4] ;  [5]
  1. Department of Physics, Nanjing University, Nanjing, 210093 China (China)
  2. Theoretical Physics Division, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918-4, Beijing, 100049 (China)
  3. Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Science, P.O. Box 918-3, Beijing, 100049 (China)
  4. Interdisciplinary Center for Theoretical Study, University of Science and Technology of China, Hefei, Anhui, 230026 China (China)
  5. Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing, 210008 China (China)
Publication Date:
OSTI Identifier:
22373394
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2014; Journal Issue: 08; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCURACY; BARYONS; COSMOLOGICAL CONSTANT; EQUATIONS OF STATE; NONLUMINOUS MATTER; OSCILLATIONS; RED SHIFT; RELICT RADIATION; SATELLITES; SUPERNOVAE