Theory of the Jitter radiation in a magnetized plasma accompanying temperature gradient

The linear stability of a magnetized plasma accompanying temperature gradient was reexamined by using plasma kinetic theory. The anisotropic velocity distribution function was decomposed into two components. One is proportional to the temperature gradient parallel to and the other is proportional to the temperature gradient perpendicular to the back ground magnetic field. Since the amplitude of the anisotropic velocity distribution function is proportional to the heat conductivity and the heat conductivities perpendicular to the magnetic field is strongly reduced, the first component of the anisotropic velocity distribution function is predominant. The anisotropic velocity distribution function induced by the temperature gradient along the back ground magnetic field drives plasma kinetic instability and the circular polarized magnetic plasma waves are excited. The instability is almost identical to Weibel instability in weakly magnetized plasma. However, depending on whether wave vectors of modes are parallel to or antiparallel to the back ground magnetic field, the growth rate is suppressed or enhanced due to back ground magnetic field. In the strongly magnetized plasma, one mode is stabilized and only one of the modes remains unstable. The Jitter radiation spectrum formulae emitted by relativistic electrons when they travel through the magnetized plasma with the plasma waves driven by the instability, are deduced at the first time. The synchrotron emission and the Jitter radiation are simultaneously emitted from the same relativistic electron. The Jitter radiation is expected to be circularly polarized but with a very small polarization degree since almost the same amount of left and right handed circular polarized magnetic waves are excited by the instability.Comment: 13 pages, 6 figures, accepted for publication in PAS

Twistors and Bi-Hermitian Surfaces of Non-K\"ahler Type

The aim of this work is to give a twistor presentation of recent results about bi-Hermitian metrics on compact complex surfaces with odd first Betti number

Nonstationary Time-Series Modeling versus Structural Equation Modeling: With an Application to Japanese Money Demand

The issues of identification, estimation, and statistical inferences of nonstationary time series and simultaneous equation models are reviewed. It is shown that prior information matters and the advantage of dichotomization of the traditional autoregressive distributed lag model into the long-run equilibrium relation and the short-run dynamic adjustment process as an empirical modeling device may be exaggerated. A Japanese money demand study is used to illustrate that a direct approach yields a more stable long-run and short-run relationship and has better predictive power than the approach of letting the data determine the long-run relationship and modeling the short-run dynamics as an adjustment of the deviation from its equilibrium position.

The Big Mac Standard: A Statistical Illustration

We demonstrate a statistical procedure for selecting the most suitable empirical model to test an economic theory, using the example of the test for purchasing power parity based on the Big Mac Index. Our results show that supporting evidence for purchasing power parity, conditional on the Balassa-Samuelson effect, depends crucially on the selection of models, sample periods and economies used for estimations.Big Mac Index, Purchasing Power Parity, Panel Data

Do Currency Regimes Matter in the 21st Century? An Overview

This paper selectively reviews the recent literature on currency regimes in Europe, the Americas, and East Asia. We argue that, given the global interdependence among today's economies, currency regimes should always be evaluated in relation to monetary policy, fiscal policy, structural policies, and the working of financial markets. Thus, currency regimes do matter and are a relevant concern for policymakers.

Asymmetric Shocks and Regional Risk Sharing: Evidence from Japan

We use the methodology of Kalemli-Ozcan, Sorensen, and Yosha ( 2003) to calculate the degree of insurance among the Japanese prefectures. Prefectural-level data for fiscal years 1975 to 1999 are used to analyze the impact of idiosyncratic shocks to regional income. The results indicate that about 20 percent of idiosyncratic shocks to regional income are absorbed by inter-regional income insurance through the capital market, about 10 percent is absorbed by the national government through the inter-regional tax transfer system, and about 60 percent is absorbed as a result of changes in saving and dissaving.

Bank Health Concerns, Low Interest Rates, and Money Demand: Evidence from the Public Opinion Survey on Household Financial Assets and Liabilities

This paper uses household survey data that cover the period from 2001 through 2003 to study the cash and deposits demand of households. These data enable us to obtain empirical findings that could not previously be derived through analyses using conventional macroeconomic time-series data. First, for asset demand, we find that the fluctuations in the extensive margin (the decisions on whether or not to hold a financial product) are sometimes more important than the fluctuations in the intensive margin (the decisions on the amounts of the financial product held). Second, we conduct detailed analyses on the causes of fluctuations in the cash demand of individual households. Third, thanks to qualitative questions in our dataset, we manage to distinguish between the fluctuations in asset demand due to low interest rates and those in response to various measures that are aimed at enhancing the safety of household savings. Fourth, we quantify the economic effects of personal financial education.Money demand; Low interest rates; Concern for the soundness of private financial institutions; Micro data; Self-selection bias; Personal financial education; Extensive margin; Intensive margin

Fractality and degree correlations in scale-free networks

Fractal scale-free networks are empirically known to exhibit disassortative degree mixing. It is, however, not obvious whether a negative degree correlation between nearest neighbor nodes makes a scale-free network fractal. Here we examine the possibility that disassortativity in complex networks is the origin of fractality. To this end, maximally disassortative (MD) networks are prepared by rewiring edges while keeping the degree sequence of an initial uncorrelated scale-free network that is guaranteed to become fractal by rewiring edges. Our results show that most of MD networks with different topologies are not fractal, which demonstrates that disassortativity does not cause the fractal property of networks. In addition, we suggest that fractality of scale-free networks requires a long-range repulsive correlation in similar degrees.Comment: 9 pages, 7 figure

Financial integration in East Asia

This paper examines the degree of integration into world financial markets and the impacts on several key macroeconomic variables of selected East Asian economies, and draws policy implications. According to our analysis, the degrees of integration into world financial markets in those economies are increasing. Regarding the impacts of increasing integration into world financial markets on several macroeconomic variables, we find three results. First, casual two-way plots among macroeconomic variables do not support the theoretical prediction of reduction in relative consumption volatility. Second, the saving-investment correlation is higher than those of in Euro area economies. Third, the degrees of smoothing of idiosyncratic shock by cross-holding of financial assets are lower than Euro area economies. Those results suggest two policy implications. First, there's some room for improvement in welfare gains in those economies by further risk sharing. Second, holding all other conditions given, the increasing integration into world financial markets alone is unlikely to provide a sound ground for a currency union in East Asia at this stage.

Aggregate and Household Demand for Money: Evidence from the Public Opinion Survey on Household Financial Assets and Liabilities

We use data from the Public Opinion Surveys on Household Financial Assets and Liabilities from 1991 to 2002 to investigate the issues of unobserved heterogeneity among cross-sectional units and stability of the Japanese aggregate money demand function. Conditions that permit individual data and aggregate data to be modeled under one consistent format are given. Alternative definitions of money are explored through year-by-year cross-sectional estimates of the Fujiki and Mulligan (1996b) household money demand model. We find that using M3 appears to be broadly consistent with time-series estimates using the aggregates constructed from the micro data. The results appear to support the existence of a stable money demand function for Japan. The estimated income elasticity for M3 is about 0.68, and five-year bond interest rate elasticity is about -0.124.Demand for money; Aggregation; Heterogeneity