Relativistic charged fluid flow. III - Generalized Hamilton-Jacobi equation

Generalized Hamilton-Jacobi equation and Clebsch transform applied to relativistic plasma flo

Spinor solution of the sound wave problem

Spinor solution of sound wave in electrically neutral ga

Monetary policy actions, macroeconomic data releases, and inflation expectations

This article analyzes how announced surprises in monetary policy actions and macroeconomic data releases affect the average rate of inflation that economic agents expect to prevail over the 10-year period following the surprise. The analysis also addresses the effect of Federal Reserve communication and surprises in monetary policy actions on perceived inflation risk over this 10-year period. The study shows that surprises in macroeconomic data releases and monetary policy actions indeed affect the expected rate of inflation. Further, there is evidence that surprises in monetary policy actions increase perceived inflation risk, whereas Federal Reserve communication reduces it.Monetary policy ; Inflation (Finance) ; Macroeconomics

Macroeconomic news and real interest rates

Economic news affects the perceptions of investors, forecasters, and policymakers about the strength or weakness of the economy. These expectations are updated on the basis of regularly occurring surprises in macroeconomic announcement data. The response of asset prices to positive or negative announcement surprises has been a regular feature of the literature for more than 20 years. In this vein, the authors evaluate the responses of the yield of 10-year Treasury inflation-indexed securities to nearly three dozen macroeconomic announcements. They find that the real long-term rate of interest responds positively to surprises in a handful of key macroeconomic indicators, including labor productivity growth. Also, the authors find no support for the proposition that the Federal Reserve has information about its actions or the state of the real economy that is not in the pubic domain and, hence, not already priced in the real long-term interest rate.Interest rates

Do productivity growth, budget deficits, and monetary policy actions affect real interest rates? evidence from macroeconomic announcement data

Real-business-cycle models suggest that an increase in the rate of productivity growth increases the real rate of interest. But economic theory is ambiguous when it comes to the effect of government budget deficits on the real rate of interest. Similarly, little is known about the effect of monetary policy actions on real long-term interest rates. We investigate these questions empirically, using macroeconomic announcement data. We find that the real long-term rate of interest responds positively to surprises in labor productivity growth. However, we do not reject the hypothesis that the real long-term rate of interest does not respond to surprises in the size of the government*s budget deficit (or surplus). Finally, we find no support for the proposition that the Federal Reserve has information about its actions or the state of the real economy that is not in the pubic domain and, hence, priced in the real long-term interest rate.Interest rates ; Monetary policy ; Fiscal policy

Kondo screening cloud in a one dimensional wire: Numerical renormalization group study

We study the Kondo model --a magnetic impurity coupled to a one dimensional wire via exchange coupling-- by using Wilson's numerical renormalization group (NRG) technique. By applying an approach similar to which was used to compute the two impurity problem we managed to improve the bad spatial resolution of the numerical renormalization group method. In this way we have calculated the impurity spin - conduction electron spin correlation function which is a measure of the Kondo compensation cloud whose existence has been a long standing problem in solid state physics. We also present results on the temperature dependence of the Kondo correlations.Comment: published versio

Spontaneous spiking in an autaptic Hodgkin-Huxley set up

The effect of intrinsic channel noise is investigated for the dynamic response of a neuronal cell with a delayed feedback loop. The loop is based on the so-called autapse phenomenon in which dendrites establish not only connections to neighboring cells but as well to its own axon. The biophysical modeling is achieved in terms of a stochastic Hodgkin-Huxley model containing such a built in delayed feedback. The fluctuations stem from intrinsic channel noise, being caused by the stochastic nature of the gating dynamics of ion channels. The influence of the delayed stimulus is systematically analyzed with respect to the coupling parameter and the delay time in terms of the interspike interval histograms and the average interspike interval. The delayed feedback manifests itself in the occurrence of bursting and a rich multimodal interspike interval distribution, exhibiting a delay-induced reduction of the spontaneous spiking activity at characteristic frequencies. Moreover, a specific frequency-locking mechanism is detected for the mean interspike interval.Comment: 8 pages, 10 figure

Dynamic Model and Phase Transitions for Liquid Helium

This article presents a phenomenological dynamic phase transition theory -- modeling and analysis -- for superfluids. As we know, although the time-dependent Ginzburg-Landau model has been successfully used in superconductivity, and the classical Ginzburg-Landau free energy is still poorly applicable to liquid helium in a quantitative sense. The study in this article is based on 1) a new dynamic classification scheme of phase transitions, 2) new time-dependent Ginzburg-Landau models for general equilibrium transitions, and 3) the general dynamic transition theory. The results in this article predict the existence of a unstable region H, where both solid and liquid He II states appear randomly depending on fluctuations and the existence of a switch point M on the lambda-curve, where the transitions changes types

Giant enhancement of hydrodynamically enforced entropic trapping in thin channels

Using our generalized Fick-Jacobs approach [Martens et al., PRL 110, 010601 (2013); Martens et al., Eur. Phys. J. Spec. Topics 222, 2453-2463 (2013)] and extensive Brownian dynamics simulations, we study particle transport through three-dimensional periodic channels of different height. Directed motion is caused by the interplay of constant bias acting along the channel axis and a pressure-driven flow. The tremendous change of the flow profile shape in channel direction with the channel height is reflected in a crucial dependence of the mean particle velocity and the effective diffusion coefficient on the channel height. In particular, we observe a giant suppression of the effective diffusivity in thin channels; four orders of magnitude compared to the bulk value.Comment: 16 pages, 8 figure

Hydrodynamically enforced entropic trapping of Brownian particles

We study the transport of Brownian particles through a corrugated channel caused by a force field containing curl-free (scalar potential) and divergence-free (vector potential) parts. We develop a generalized Fick-Jacobs approach leading to an effective one-dimensional description involving the potential of mean force. As an application, the interplay of a pressure-driven flow and an oppositely oriented constant bias is considered. We show that for certain parameters, the particle diffusion is significantly suppressed via the property of hyrodynamically enforced entropic particle trapping.Comment: 5 pages, 4 figures, in press with Physical Review Letter