Age of the Universe in the Cardassian Model

Abstract

The age of the universe is obtained in a subset of Cardassian models by using WMAP data. Cardassian expansion is a modification to the Friedmann equation that allows the universe to be flat, matter dominated, and accelerating, without a vacuum component. Since this model changes the evolution of the universe, we should not a priori expect the Cardassian age to be the same as the WMAP Friedmann derived result of 13.7 +/- 0.2 Gyrs. However, in the subset of Cardassian models we consider, we discover that the age of the universe varies from 13.4 - 13.8 Gyr over the range of parameter space we explore, a result close to that of the standard Lambda Cold Dark Matter model. The Hubble constant h, which may also vary in these models, likewise varies little from the Friedmann result.

11 pages, two eps figures. v2: clarified choice of parameters, other minor changes. v3: added references, other changes to match version to be published in JCAP

References in corpus (9)

• Cosmological parameters from SDSS and WMAP
• Cosmology and the Fate of Dilatation Symmetry
• A comparison of cosmological models using recent supernova data
• The Fate of Bound Systems in Phantom and Quintessence Cosmologies
• Observational constraints on cosmology from modified Friedmann equation
• Supernova constraints on alternative models to dark energy
• The CMB spectrum in Cardassian models
• Constraints on alternative models to dark energy
• Combined constraints on Cardassian models from supernovae, CMB and large-scale structure observations

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• Chain inflation and the imprint of fundamental physics in the CMBR
• Tunneling and propagation of vacuum bubbles on dynamical backgrounds
• Chain Inflation Reconsidered
• Constraints on Cardassian universe from Gamma ray bursts
• Latest Observational Constraints on Cardassian Models
• "Old" Locked Inflation
• Observing the Structure of the Landscape with the CMB Experiments
• Latest Cosmological Constraints on Cardassian expansion models including the updated Gamma-ray bursts
• Dark Energy, Hyperbolic Cosecant Cardassian and Virial Collapse for Power-style Cardassian