Earthquake cycles and neural reverberations

Driven systems of interconnected blocks with stick-slip friction capture main features of earthquake processes. The microscopic dynamics closely resemble those of spiking nerve cells. We analyze the differences in the collective behavior and introduce a class of solvable models. We prove that the models exhibit rapid phase locking, a phenomenon of particular interest to both geophysics and neurobiology. We study the dependence upon initial conditions and system parameters, and discuss implications for earthquake modeling and neural computation

The FOMC in 1996: "watchful waiting"

In light of recent research findings, Michael J. Dueker and Andreas M. Fischer review the 1996 policy posture of the Federal Open Market Committee (FOMC), the monetary policymaking body of the Federal Reserve System. They find several areas in which the FOMC's policy positions were consistent with the conclusions of recent research studies, whether or not these studies directly influenced the Committee's thinking. In general, the authors conclude that the FOMC intended to ensure that inflation was contained near 3 percent in 1996 but did not intend to bring down the trend rate of inflation that year.Federal Open Market Committee ; Inflation (Finance) ; Monetary policy - United States ; Consumer price indexes

Do inflation targeters outperform non-targeters?

Ten years of empirical studies of inflation targeting have not uncovered clear evidence that monetary policy that incorporates formal targets imparts better inflation performance. The authors survey the literature and find that the "no difference" verdict concerning inflation targeting has been robust to a wide range of countries and methods of analysis, starting with a study by Dueker and Fischer (1996a). The authors present updated Markov-switching estimates from the original Dueker and Fischer (1996a) article and show that their early conclusions about inflation targeting among early adopters have not been overturned with an additional decade of data. These findings to date do not rule out the possibility, however, that formal inflation targets could prove pivotal if the global environment of disinflation were to reverse course.Inflation (Finance)

Open mouth operations: a Swiss case study

Financial markets ; Switzerland

A guide to nominal feedback rules and their use for monetary policy

If price stability is to be sustained, monetary policy actions will inevitably resemble - in the long run - the prescriptions from nominal feedback rules, which are designed to achieve price stability. This property means that monetary policy might be well described by a nominal feedback rule in a low-inflation country such as Switzerland. In this article, Michael J. Dueker an Andreas M. Fischer provide a general description of nominal feedback rules and use one rule - with time-varying parameters - to model Swiss monetary policy actions. The authors explain how this indicator model can presage a buildup of inflationary pressures before they become obvious through other traditional policy indicators.Monetary policy ; Switzerland

Fixing Swiss potholes: the importance of improvements

This note sheds new light on the dynamic properties of maintenance and repair and examines the behavior of an additional form of capital spending-that of improvements. The analysis examines a unique long-run data set on Swiss road spending.Capital

Theoretical study of impurity-induced magnetism in FeSe

Experimental evidence suggests that FeSe is close to a magnetic instability, and recent scanning tunneling microscopy (STM) measurements on FeSe multilayer films have revealed stripe order locally pinned near defect sites. Motivated by these findings, we perform a theoretical study of locally induced magnetic order near nonmagnetic impurities in a model relevant for FeSe. We find that relatively weak repulsive impurities indeed are capable of generating short-range magnetism, and explain the driving mechanism for the local order by resonant eg-orbital states. In addition, we investigate the importance of orbital-selective self-energy effects relevant for Hund's metals, and show how the structure of the induced magnetization cloud gets modified by orbital selectivity. Finally, we make concrete connection to STM measurements of iron-based superconductors by symmetry arguments of the induced magnetic order, and the basic properties of the Fe Wannier functions relevant for tunneling spectroscopy.Comment: 10 pages, 4 figure

Robustness of Quasiparticle Interference Test for Sign-changing Gaps in Multiband Superconductors

Recently, a test for a sign-changing gap function in a candidate multiband unconventional superconductor involving quasiparticle interference data was proposed. The test was based on the antisymmetric, Fourier transformed conductance maps integrated over a range of momenta $\bf q$ corresponding to interband processes, which was argued to display a particular resonant form, provided the gaps changed sign between the Fermi surface sheets connected by $\bf q$. The calculation was performed for a single impurity, however, raising the question of how robust this measure is as a test of sign-changing pairing in a realistic system with many impurities. Here we reproduce the results of the previous work within a model with two distinct Fermi surface sheets, and show explicitly that the previous result, while exact for a single nonmagnetic scatterer and also in the limit of a dense set of random impurities, can be difficult to implement for a few dilute impurities. In this case, however, appropriate isolation of a single impurity is sufficient to recover the expected result, allowing a robust statement about the gap signs to be made.Comment: 9 pages, 12 figure

Edge Mode Combinations in the Entanglement Spectra of Non-Abelian Fractional Quantum Hall States on the Torus

We present a detailed analysis of bi-partite entanglement in the non-Abelian Moore-Read fractional quantum Hall state of bosons and fermions on the torus. In particular, we show that the entanglement spectra can be decomposed into intricate combinations of different sectors of the conformal field theory describing the edge physics, and that the edge level counting and tower structure can be microscopically understood by considering the vicinity of the thin-torus limit. We also find that the boundary entropy density of the Moore-Read state is markedly higher than in the Laughlin states investigated so far. Despite the torus geometry being somewhat more involved than in the sphere geometry, our analysis and insights may prove useful when adopting entanglement probes to other systems that are more easily studied with periodic boundary conditions, such as fractional Chern insulators and lattice problems in general.Comment: 13 pages, 8 figures, published version on PR