Latest Observational Constraints on Cardassian Models

Abstract

Constraints on the original Cardassian model and the modified polytropic Cardassian model are examined from the latest derived 397 Type Ia supernova (SNe Ia) data, the size of baryonic acoustic oscillation peak from the Sloan Digital Sky Survey (SDSS), the position of first acoustic peak of the Cosmic Microwave Background radiation (CMB) from the five years Wilkinson Microwave Anisotropy Probe (WMAP), the x-ray gas mass fractions in clusters of galaxies, and the observational H(z) data. In the original Cardassian model with these combined data set, we find ${\Omega }_{m0}=0.271_{-0.014}^{+0.014},n=0.035_{-0.049}^{+0.049}$ at $1\sigma$ confidence level. And in the modified polytropic Cardassian model, we find that ${\Omega }_{m0}=0.271_{-0.015}^{+0.014}$, $n=-0.091_{-1.908}^{+0.331}$ and $\beta =0.824_{-0.622}^{+0.750}$ within $1\sigma$ confidence level. According to these observations, the acceleration of the universe begins at $z_T=0.55_{-0.05}^{+0.05}(1\sigma )$ for the original Cardassian model, and at $z_T=0.58_{-0.12}^{+0.12}(1\sigma )$ for the modified polytropic Cardassian model. Evolution of the effective equation of state $w_{eff}$ for the modified polytropic Cardassian model is also examined here and results show that an evolutionary quintessence dark energy model is favored.

13pages, 7figs

References in corpus (8)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Improved Cosmological Constraints from New, Old and Combined Supernova Datasets
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• Statefinder diagnostic for the modified polytropic Cardassian universe
• Observational constraints on modified gravity models and the Poincaré dodecahedral topology
• Large-scale structure and the Cardassian fluid

Cited by in corpus (6)

• Testing the phenomenological interacting dark energy with observational $H(z)$ data
• Testing nonstandard cosmological models with SNLS3 supernova data and other cosmological probes
• A magnified glance into the dark sector: probing cosmological models with strong lensing in A1689
• Cardassian Universe Constrained by Latest Observations
• Thermodynamic Origin of the Cardassian Universe
• Latest Cosmological Constraints on Cardassian expansion models including the updated Gamma-ray bursts