Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-09-27
Abstract： We construct the non-canonical kinetic term of a k-essence field directly from the effective equation of state function wk(z), which describes the properties of the dark energy.Adopting the usual parametrizations of equation of state we numerically reproduce the shape of the non-canonical kinetic term and discuss some features of the constructed form of k-essence.
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Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-09-27
Abstract： We develop a theoretical method of constructing the quintessence potential directly from the effective equation of state function w(z), which describes the properties of the dark energy. We apply our method to four parametrizations of equation of state parameter and discuss the general features of the resulting potentials. In particular, it is shown that the constructed quintessence potentials are all in the form of a runaway type.
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-09-27
Abstract： We derive the Boltzmann equation in the synchronous gauge for massive neutrinos with a deformed dispersion relation. Combining the 7-year WMAP data with lower-redshift measurements of the expansion rate, we give constraints on the deformation parameter and find that the deformation parameter is strong degenerate with the physical dark matter density rather than the neutrino mass. Our results show that there is no evidence for Lorentz invariant violation in the neutrino sector. The ongoing Planck experiment could provide improved constraints on the deformation parameter.
Peer Review Status:Awaiting Review
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2017-09-27
Abstract： We reconstruct the shape of the primordial power spectrum of curvature perturbations in extended cosmological models, including addition of massive neutrinos, extra relativistic species or varying primordial helium abundance, from the latest cosmic microwave background data from the Wilkinson Microwave Anisotropy Probe, the Atacama Cosmology Telescope and the South Pole Telescope. We find that a scale-invariant primordial spectrum is disfavored by the data at 95% confidence level even in the presence of massive neutrinos, however it can lie within the 95% confidence region if the effective number of relativistic species or the primordial helium abundance is allowed to vary freely. The constraints on the extension parameters from WMAP7+ACT+H0+BAO, are the total mass of neutrinos Mν < 0.48 eV (95% CL), the effective number of relativistic species Neff = 4.50 ± 0.81 and the primordial helium abundance Yp = 0.303 ± 0.075. The constraints from WMAP7+SPT+H0+BAO, are Mν < 0.45 eV (95% CL), Neff = 3.86±0.63 and Yp = 0.277±0.050.
Peer Review Status:Awaiting Review
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