The dynamical Casimir effect in superconducting microwave circuits

We theoretically investigate the dynamical Casimir effect in electrical circuits based on superconducting microfabricated waveguides with tunable boundary conditions. We propose to implement a rapid modulation of the boundary conditions by tuning the applied magnetic flux through superconducting quantum interference devices (SQUIDs) that are embedded in the waveguide circuits. We consider two circuits: (i) An open waveguide circuit that corresponds to a single mirror in free space, and (ii) a resonator coupled to a microfabricated waveguide, which corresponds to a single-sided cavity in free space. We analyze the properties of the dynamical Casimir effect in these two setups by calculating the generated photon-flux density, output-field correlation functions, and the quadrature squeezing spectra. We show that these properties of the output field exhibit signatures unique to the radiation due to the dynamical Casimir effect, and could therefore be used for distinguishing the dynamical Casimir effect from other types of radiation in these circuits. We also discuss the similarities and differences between the dynamical Casimir effect, in the resonator setup, and downconversion of pump photons in parametric oscillators.Comment: 18 pages, 14 figure

Stock and Bond Relationships in Asia

This paper analyzes the relationship between stocks and bonds in nine Asian countries. Using a bivariate stochastic volatility model, we show that there are significant volatility spillover effects between stock and bond markets in several of the countries. Furthermore, dynamic correlation patterns show that the relationship between stock and bond markets changes considerably over time in all countries. Stock-bond correlation increases during periods of turmoil in several countries, indicating that there is a cross-asset contagion effect. Therefore, if there is a flight to quality effect in Asian markets, it seems to occur across countries or regions rather than across domestic assets. The results have direct and important implications for regional policy makers as well as domestic and international investors that invest in multiple asset classes.Asia; stock markets; bond markets; stochastic volatility; Markov Chain Monte Carlo; spillover effects; dynamic correlation

MECHANISM DESIGN FOR NUTRIENT TRADING UNDER ASYMMETRIC INFORMATION

The objective of this paper is to evaluate first- and second-best trading mechanisms for regulating point and nonpoint source phosphorus emissions. The trading mechanisms are differentiated on the degree to which regulators can observe abatement efforts. The deadweight losses attributable to informational asymmetries and those of the second-best mechanisms will provide regulators the shadow value of foregoing first-best measures.Environmental Economics and Policy,

Asian Sovereign Debt and Country Risk

This paper analyzes systematic risk of sovereign bonds in four East Asian countries: China, Malaysia, Philippines, and Thailand. A bivariate stochastic volatility model that allows for time-varying correlation is estimated with Markov Chain Monte Carlo simulation. The volatilities and correlation are then used to calculate the time-varying betas. The results show that country-specific systematic risk in Asian sovereign bonds varies over time. When adjusting for inherent exchange rate risk, the pattern of systematic risk is similar, even though the level is generally lower. The findings have important implications for international portfolio managers that invest in emerging sovereign bonds and those who need benchmark instruments to analyze risk in assets such as corporate bonds in the emerging Asian financial markets.Asia; sovereign bonds; systematic risk; stochastic volatility; Markov Chain Monte Carlo

Participant Bidding Enhances Cost Effectiveness

A multitude of design decisions influence the performance of voluntary conservation programs. This Economic Brief is one of a set of five exploring the implications of decisions policymakers and program managers must make about who is eligible to receive payments, how much can be received, for what action, and the means by which applicants are selected. The particular issue examined here is the potential benefits of allowing farmers to "bid" for the activity they will undertake and the level of payment they would receive for it.Agricultural and Food Policy, Environmental Economics and Policy,

Watershed Nutrient Trading Under Asymmetric Information

This study evaluates first- and second-best trading policies for regulating watershed phosphorus under asymmetric information. The trading policies are differentiated on the degree to which regulators observe point and nonpoint source abatement efforts. The efficiency losses attributable to these informational asymmetries and those of the second-best policies can be measured in social welfare, and provide regulators the shadow value of foregoing first-best measures. Given representative monitoring costs from national water monitoring programs, it is shown that under asymmetric information, the chosen second-best trading policies outperform first-best policies by 11% in the control of watershed nutrient pollution.Environmental Economics and Policy,

CHINA'S FINANCIAL MARKET INTEGRATION WITH THE WORLD

It is commonly argued that China's financial markets are effectively insulated from the rest of the world. To see if this is true and to better understand China's financial development, we analyze China's integration with major financial markets. Using conditional copulas, we show that China has experienced an increasing level of integration with several major financial markets during the last decade, even though the country's financial markets are commonly seen as being insulated. Furthermore, the level of integration has increased with several major markets during the current financial crisis. The results and possible reasons for the increasing integration are analyzed and the implications for policymakers and market participants are discussed.China; financial market integration; codependence; copula

Fast and accurate evaluation of Wigner 3j, 6j, and 9j symbols using prime factorisation and multi-word integer arithmetic

We present an efficient implementation for the evaluation of Wigner 3j, 6j, and 9j symbols. These represent numerical transformation coefficients that are used in the quantum theory of angular momentum. They can be expressed as sums and square roots of ratios of integers. The integers can be very large due to factorials. We avoid numerical precision loss due to cancellation through the use of multi-word integer arithmetic for exact accumulation of all sums. A fixed relative accuracy is maintained as the limited number of floating-point operations in the final step only incur rounding errors in the least significant bits. Time spent to evaluate large multi-word integers is in turn reduced by using explicit prime factorisation of the ingoing factorials, thereby improving execution speed. Comparison with existing routines shows the efficiency of our approach and we therefore provide a computer code based on this work.Comment: 7 pages, 2 figures. Accepted for publication in SIAM Journal on Scientific Computing (SISC

Nonclassical microwave radiation from the dynamical Casimir effect

We investigate quantum correlations in microwave radiation produced by the dynamical Casimir effect in a superconducting waveguide terminated and modulated by a superconducting quantum interference device. We apply nonclassicality tests and evaluate the entanglement for the predicted field states. For realistic circuit parameters, including thermal background noise, the results indicate that the produced radiation can be strictly nonclassical and can have a measurable amount of intermode entanglement. If measured experimentally, these nonclassicalilty indicators could give further evidence of the quantum nature of the dynamical Casimir radiation in these circuits.Comment: 5 pages, 3 figure

CHINA'S OFFICIAL RATES AND BOND YIELDS

Recent research shows that bond yields are influenced by monetary policy decisions. To learn how this works in an interest rate market that differs significantly from that of the U.S. and Europe, we model Chinese bond yields using the one-year deposit rate as a state variable. We also add the difference between the one-year interest rate and the one-year deposit rate as a factor. The model is developed in an affine framework and closed-form solutions are obtained. It is tested empirically and the results show that the new model characterizes the changing shape of the yield curve well. Incorporating the benchmark rate into the model thus helps us to match Chinese bond yields.China; deposit rate; bond yields; jump process; affine model