Expectations for the Difference Between Local and Global Measurements of the Hubble Constant

There are irreducible differences between the Hubble constant measured locally and the global value. They are due to density perturbations and finite sample volume (cosmic variance) and finite number of objects in the sample (sampling variance). We quantify these differences for a suite of COBE-normalized CDM models that are consistent with the observed large-scale structure. For small samples of objects that only extend out to 10,000 km/sec, the variance can approach 4%. For the largest samples of Type Ia supernovae (SNeIa), which include about 40 objects and extend out to almost 40,000 km/sec, the variance is 1-2% and is dominated by sampling variance. Sampling and cosmic variance may be an important consideration in comparing local determinations of the Hubble constant with precision determinations of the global value that will be made from high-resolution maps of CBR anisotropy.Comment: 10 pages, Latex, 2 figures, version accepted for Ap.

Enhancement of Transition Temperature in FexSe0.5Te0.5 Film via Iron Vacancies

The effects of iron deficiency in FexSe0.5Te0.5 thin films (0.8<x<1) on superconductivity and electronic properties have been studied. A significant enhancement of the superconducting transition temperature (TC) up to 21K was observed in the most Fe deficient film (x=0.8). Based on the observed and simulated structural variation results, there is a high possibility that Fe vacancies can be formed in the FexSe0.5Te0.5 films. The enhancement of TC shows a strong relationship with the lattice strain effect induced by Fe vacancies. Importantly, the presence of Fe vacancies alters the charge carrier population by introducing electron charge carriers, with the Fe deficient film showing more metallic behavior than the defect-free film. Our study provides a means to enhance the superconductivity and tune the charge carriers via Fe vacancy, with no reliance on chemical doping.Comment: 15 pages, 4 figure

Robust Preparation of GHZ and W States of Three Distant Atoms

Schemes to generate Greenberger-Horne-Zeilinger(GHZ) and W states of three distant atoms are proposed in this paper. The schemes use the effects of quantum statistics of indistinguishable photons emitted by the atoms inside optical cavities. The advantages of the schemes are their robustness against detection inefficiency and asynchronous emission of the photons. Moreover, in Lamb-Dicke limit, the schemes do not require simultaneous click of the detectors, this makes the schemes more realizable in experiments.Comment: 5 pages, 1 fiure. Phys. Rev. A 75, 044301 (2007

Quantum state engineering with flux-biased Josephson phase qubits by Stark-chirped rapid adiabatic passages

In this paper, the scheme of quantum computing based on Stark chirped rapid adiabatic passage (SCRAP) technique [L. F. Wei et al., Phys. Rev. Lett. 100, 113601 (2008)] is extensively applied to implement the quantum-state manipulations in the flux-biased Josephson phase qubits. The broken-parity symmetries of bound states in flux-biased Josephson junctions are utilized to conveniently generate the desirable Stark-shifts. Then, assisted by various transition pulses universal quantum logic gates as well as arbitrary quantum-state preparations could be implemented. Compared with the usual PI-pulses operations widely used in the experiments, the adiabatic population passage proposed here is insensitive the details of the applied pulses and thus the desirable population transfers could be satisfyingly implemented. The experimental feasibility of the proposal is also discussed.Comment: 9 pages, 4 figure

Energy price, regulatory price distortion and economic growth: A case study of China

© 2017 Elsevier B.V. Energy prices are often distorted by government control, which is justified on the grounds that such control will help mitigate the negative impact of price volatility from oil imports, and thus positively affect the domestic economy. In this paper, we show in a two-sector growth model, that regulatory price distortion can negatively affect the economy, and then, based on the model, we empirically estimate the impact of the price distortion on output growth in China, using monthly, time series data from 2005M1 to 2012M12. In contrast to the usual argument for regulatory control to mitigate price volatility, we find that regulatory price distortion negatively affects output growth in China during both the short and long term, because it is robust to different measures of output and price distortion. Hence, the argument that using price regulation to protect economic growth is undermined, and subsequently, this study lends its support to energy price deregulation. A market oriented energy price regime may improve the resilience of the domestic economy to global oil price shocks

Intangible capital and sectoral energy intensity: Evidence from 40 economies between 1995 and 2007

© 2018 Elsevier Ltd Intangible capital has been found to be an increasingly important source of productivity and economic growth. However, its effects on energy intensity have received little attention. Given the importance of reducing energy intensity, this study advances the understanding of the relationship between intangible capital and sectoral energy intensity by taking advantage of a rich dataset of 40 economies derived from the World Input-Output Database (WIOD), spanning across 13 years (1995–2007). A relatively robust causal relationship between intangible capital and sectoral energy intensity has been identified. The qualitative and quantitative interactions of this relationship with income level and sectoral heterogeneity have also been revealed. It is found that the effect of intangible capital on reducing sectoral energy intensity generally diminishes along with increasing income level but a moderate quadratic relationship is identified in some types of intangible capital. Finally, sectors where intangible capital have the largest and smallest effect are also pinpointed