ar X iv : a st ro - p h / 04 10 40 8 v 2 2 1 D ec 2 00 4 Combined constraints on Cardassian models from supernovae , CMB and large - scale structure observations
نویسندگان
چکیده
We confront Cardassian models with recent observational data. These models can be viewed either as purely phenomenological modifications of the Friedmann equation, or as arising from cosmic fluids with non-standard properties. In the first case, we find that the models are consistent with the data for a wide range of parameters but no significant preference over the ΛCDM model is found. In the latter case we find that the fact that the sound speed is non-zero in these models makes them inconsistent with the galaxy power spectrum from the Sloan Digital Sky Survey.
منابع مشابه
ar X iv : a st ro - p h / 04 10 40 8 v 1 1 8 O ct 2 00 4 Combined constraints on Cardassian models from supernovae , CMB and large - scale structure observations
We confront Cardassian models with recent observational data. These models can be viewed either as purely phenomenological modifications of the Friedmann equation, or as arising from cosmic fluids with non-standard properties. In the first case, we find that the models are consistent with the data for a wide range of parameters but no significant preference over the ΛCDM model is found. In the ...
متن کاملar X iv : a st ro - p h / 04 08 14 1 v 1 7 A ug 2 00 4 Weak Lensing and Supernovae : Complementary Probes of Dark Energy
Weak lensing observations and supernova observations, combined with CMB observations, can both provide powerful constraints on dark energy properties. Considering statistical errors only, we find luminosity distances inferred from 2000 supernovae and large-scale (l < 1000) angular power spectra inferred from redshift-binned cosmic shear maps place complementary constraints on w 0 and w a where ...
متن کاملar X iv : a st ro - p h / 04 03 02 4 v 1 1 M ar 2 00 4 On coordinate distances to type Ia supernovae and radio galaxies
Quantum model of homogeneous and isotropic universe predicts logarithmic-law dependence of coordinate distance to source on redshift z which is in good agreement with type Ia supernovae and radio galaxies observations for the redshift range z = 0.01 − 1.8. Comparison with phenomenological models with dark energy in the form of cosmological constant and without dark energy component is made. Flu...
متن کاملar X iv : a st ro - p h / 05 04 59 7 v 1 2 7 A pr 2 00 5 Supernovae : Explosions in the Cosmos
In this article, a broad perspective of supernovae, their classification and mechanism is given. Later, the astrophysical significance of supernovae is discussed in brief.
متن کاملar X iv : a st ro - p h / 04 10 41 3 v 1 1 8 O ct 2 00 4 Quantum - Gravity phenomenology and high energy particle propagation
Quantum-gravity effects may introduce relevant consequences for the propagation and interaction of high energy cosmic rays particles. Assuming the space-time foamy structure results in an intrinsic uncertainty of energy and momentum of particles, we show how low energy (under GZK) observations can provide strong constraints on the role of the fluctuating space-time structure.
متن کامل