NEW CONSTRAINTS ON THE VARIABLE EQUATION OF STATE PARAMETER FROM X-RAY GAS MASS FRACTIONS AND SNe Ia

2006/08/31 by J. V. Cunha, J. V. CUNHA, L. Marassi +3 · 3 citations
Physics and Astronomy · #Component (thermodynamics) #Cosmology and Gravitation Theories #Dark energy #Equation of state #Function (biology) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gamma-ray bursts and supernovae #Luminosity #Type (biology) #Variable (mathematics) #astro-ph

paper · pdf · doi:10.1142/s0218271807010183

published as Int.J.Mod.Phys.D16:403-409,2007 · paper, 6 pages, 1 figure Accepted by Int. Journal of Modern Physics D (IJPMD)

arxiv created 2006/08/31 · openalex publication_date 2007/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05

Abstract

Recent measurements are suggesting that we live in a flat Universe and that its present accelerating stage is driven by a dark energy component whose equation of state may evolve in time. Assuming two different parametrizations for the function ω(z), we constrain their free parameters from a joint analysis involving measurements from X-ray luminosity of galaxy clusters and SNe type Ia data.

Citations

• Cosmological Constant - the Weight of the Vacuum
• Cosmological implications of APM 08279+5255, an old quasar at z = 3.91
• The cosmological constant and dark energy
• First‐Year Wilkinson Microwave Anisotropy Probe ( WMAP ) Observations: Preliminary Maps and Basic Results
• A theoretician's analysis of the supernova data and the limitations in determining the nature of dark energy
• Final Results from theHubble Space TelescopeKey Project to Measure the Hubble Constant
• A flat Universe from high-resolution maps of the cosmic microwave background radiation

Cited by

• Transition redshift: new kinematic constraints from supernovae
• Constraints on a possible evolution of mass density power-law index in strong gravitational lensing from cosmological data
• Clustering, angular size, and dark energy