12,094 research outputs found
Is Cosmological Constant Needed in Higgs Inflation?
The detection of B-mode shows a very powerful constraint to theoretical
inflation models through the measurement of the tensor-to-scalar ratio .
Higgs boson is the most likely candidate of the inflaton field. But usually,
Higgs inflation models predict a small value of , which is not quite
consistent with the recent results from BICEP2. In this paper, we explored
whether a cosmological constant energy component is needed to improve the
situation. And we found the answer is yes. For the so-called Higgs chaotic
inflation model with a quadratic potential, it predicts ,
with e-folds number , which is large enough to
overcome the problems such as the horizon problem in the Big Bang cosmology.
The required energy scale of the cosmological constant is roughly , which means a mechanism is still needed to solve the
fine-tuning problem in the later time evolution of the universe, e.g. by
introducing some dark energy component.Comment: 4 pages, 2 figure
Reexploration of interacting holographic dark energy model: Cases of interaction term excluding the Hubble parameter
In this paper, we make a deep analysis for the five typical interacting
holographic dark energy models with the interaction terms , , , , and , respectively.
We obtain observational constraints on these models by using the type Ia
supernova data (the Joint Light-curve Analysis sample), the cosmic microwave
background data (Planck 2015 distance priors), the baryon acoustic oscillations
data, and the direct measurement of the Hubble constant. We find that the
values of for all the five models are almost equal
(around~699), indicating that the current observational data equally favor
these IHDE models. In addition, a comparison with the cases of interaction term
involving the Hubble parameter is also made.Comment: 14 pages, 6 figures. arXiv admin note: text overlap with
arXiv:1710.0306
Weak Measurement of Qubit Oscillations with Strong Response Detectors: Violation of the Fundamental Bound Imposed on Linear Detectors
We investigate the continuous weak measurement of a solid-state qubit by
single electron transistors in nonlinear response regime. It is found that the
signal-to-noise ratio can violate the universal upper bound imposed quantum
mechanically to any linear response detectors. We understand the violation by
means of the cross-correlation of the detector currents.Comment: 4 pages, 4 figure
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