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Cosmological CPT Violation, Baryon/Leptogenesis and CMB Polarization
In this paper we study the cosmological CPT-violation and its implications in
baryo/leptogenesis and CMB polarization. We propose specifically a variant of
the models of gravitational leptogenesis. By performing a global analysis with
the Markov Chain Monte Carlo (MCMC) method, we find the current CMB
polarization observations from the three-year WMAP (WMAP3) and the 2003 flight
of BOOMERANG (B03) data provide a weak evidence for our model. However to
verify and especially exclude this type of mechanism for baryo/leptogenesis
with cosmological CPT-violation, the future measurements on CMB polarization
from PLANCK and CMBpol are necessary.Comment: The version appears in PL
Probing for the Cosmological Parameters with PLANCK Measurement
We investigate the constraints on cosmological parameters especially for EoS
of dark energy, inflationary parameters, neutrino mass and curvature of
universe using simulated Planck data. Firstly we determine cosmological
parameters with current observations including ESSENCE, WMAP3, Boomerang-2K2,
CBI, VSA, ACBAR, SDSS LRG and 2dFGRS, and take best-fit model as the fiducial
model in simulations. In simulations we pay attention to the effects of
dynamical dark energy in determination of cosmological parameters. We add
simulated SNAP data to do all the simulations. Using present data, we find
Quintom dark energy model is mildly favored while \LambdaCDM remains a good
fit. In the framework of dynamical dark energy, the constraints on inflationary
parameters, m_{\nu} and \Omega_{K} become weak compared with the constraints in
\LambdaCDM. Intriguingly, we find that the inflationary models with a "blue"
tilt, which are excluded about 2\sigma in \LambdaCDM model, are well within
2\sigma region with the presence of the dynamics of dark energy. The upper
limits of neutrino mass are weakened by a factor of 2 (95% C.L.), say,
m_{\nu}<1.59 eV and m_{\nu}<1.53 eV for two forms of parametrization of the
equation of state of dark energy. The flat universe is a good fit to the
current data, namely, |\Omega_{K}|<0.03 (95% C.L.). With the simulated Planck
and SNAP data, dynamical dark energy and \LambdaCDM might be distinguished at
4\sigma. And uncertainties of inflationary parameters, m_{\nu} and \Omega_{K}
can be reduced obviously. We also constrain the rotation angle \Delta\alpha,
denoting possible cosmological CPT violation, with simulated Planck and CMBpol
data and find that our results are much more stringent than current constraint
and will verify cosmological CPT symmetry with a higher precision. (Abridged)Comment: 15 pages, 8 figures and 3 tables, Accepted for publication in
Int.J.Mod.Phys.
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