7,586 research outputs found
Observational Constraints on Varying Alpha in CDM Cosmology
In this work, we consider the so-called CDM cosmology with
while the fine-structure "constant" is
varying. In this scenario, the accelerated expansion of the universe is driven
by the cosmological "constant" (equivalently the vacuum energy), and
the varying is driven by a subdominant scalar field coupling
with the electromagnetic field. The observational constraints on the varying
and models with various couplings
between the subdominant scalar field and the electromagnetic
field are considered.Comment: 13 pages, 5 figures, 1 table, revtex4; v2: appendix removed, Commun.
Theor. Phys. in press; v3: published version. arXiv admin note: text overlap
with arXiv:1605.0457
Three-generation neutrino oscillations in curved spacetime
Three-generation MSW effect in curved spacetime is studied and a brief
discussion on the gravitational correction to the neutrino self-energy is
given. The modified mixing parameters and corresponding conversion
probabilities of neutrinos after traveling through celestial objects of
constant densities are obtained. The method to distinguish between the normal
hierarchy and inverted hierarchy is discussed in this framework. Due to the
gravitational redshift of energy, in some extreme situations, the resonance
energy of neutrinos might be shifted noticeably and the gravitational effect on
the self-energy of neutrino becomes significant at the vicinities of spacetime
singularities.Comment: 25 pages, 5 figures, 2 tables. Some changes are made according to
referee's suggestions. The final version is to be published at Nuclear
Physics
Short note on two output-dependent hidden Markov models
The purpose of this note is to study the assumption of mutual information independence", which is used by Zhou (2005) for deriving an output-dependent hidden Markov model, the so-called discriminative HMM (D-HMM), in the context of determining a stochastic optimal sequence of hidden states. The assumption is extended to derive its generative counterpart, the G-HMM. In addition, state-dependent representations for two output-dependent HMMs, namely HMMSDO (Li, 2005) and D-HMM, are presented
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