Quintessence and variation of the fine structure constant in the cosmic microwave background radiation
نویسندگان
چکیده
منابع مشابه
Sensitivity of the Cosmic Microwave Background Anisotropy to Initial Conditions in Quintessence Cosmology
We analyze the evolution of energy density fluctuations in cosmological scenarios with a mixture of cold dark matter and quintessence, in which the quintessence field is modeled by a constant equation of state. We obtain analytic expressions for the time evolution of the quintessence perturbations in models with light fields. The fluctuations behave analogously to a driven harmonic oscillator, ...
متن کاملNew Constraints on Spatial Variations of the Fine Structure Constant from Clusters of Galaxies
We have constrained the spatial variation of the fine structure constant using multi-frequency measurements of the thermal Sunyaev-Zeldovich effect of 618 X-ray selected clusters. Although our results are not competitive with the ones from quasar absorption lines, we improved by a factor 10 and ∼2.5 previous results from Cosmic Microwave Background power spectrum and from galaxy clusters, respe...
متن کاملar X iv : a st ro - p h / 03 02 26 4 v 2 6 J un 2 00 3 Quintessence and the Curvature of the Universe after WMAP
Received (received date) Revised (revised date) We study quintessence models with a constant (effective) equation of state. It is investigated whether such quintessence models are consistent with a negative spatial curvature of the Universe with respect to the anisotropy of the cosmic microwave background radiation measured by the WMAP mission. If the reionization is negligibly small, it is fou...
متن کاملCoupled Quintessence
A new component of the cosmic medium, a light scalar field or ”quintessence ”, has been proposed recently to explain cosmic acceleration with a dynamical cosmological constant. Such a field is expected to be coupled explicitely to ordinary matter, unless some unknown symmetry prevents it. I investigate the cosmological consequences of such a coupled quintessence (CQ) model, assuming an exponent...
متن کاملConstraints on time variation of fine structure constant from WMAP-3yr data
This paper presents the constraints on the time variation of the fine structure constant at recombination relative to its present value, ∆α = (αrec − α0)/α0, obtained from the analysis of the WMAP-3yr Cosmic Microwave Background (CMB) data, with an additional prior on the Hubble expansion rate from HST Hubble Key Project. I found out that −0.039 < ∆α < 0.010 at 95% C.L., which brings a 30% impr...
متن کامل