The internal Compton effect

Internal Compton effect, and use of superconducting magnet spectrometer to determine multipolarity assignment

Systematical, experimental investigations on LiMgZ (Z= P, As, Sb) wide band gap semiconductors

This work reports on the experimental investigation of the wide band gap compounds LiMgZ (Z = P, As, Sb), which are promising candidates for opto-electronics and anode materials for Lithium batteries. The compounds crystallize in the cubic (C1_b) MgAgAs structure (space group F-43m). The polycrystalline samples were synthesized by solid state reaction methods. X-ray and neutron diffraction measurements show a homogeneous, single-phased samples. The electronic properties were studied using the direct current (DC) method. Additionally UV-VIS diffuse reflectance spectra were recorded in order to investigate the band gap nature. The measurements show that all compounds exhibit semiconducting behavior with direct band gaps of 1.0 eV to 2.3 eV depending on the Z element. A decrease of the peak widths in the static 7Li nuclear magnetic resonance (NMR) spectra with increasing temperature was observed, which can directly be related to an increase of Li ion mobility.Comment: 8 page

Banking system stability: A cross-atlantic perspective

Paper prepared for the NBER project on “Risks of Financial Institutions”. We benefited from suggestions and criticism by many participants in the NBER project on “Risks of financial institutions”, in particular by the organizers Mark Carey (also involving Dean Amel and Allen Berger) and Rene Stulz, by our discussant Tony Saunders and by Patrick de Fontnouvelle, Gary Gorton, Andy Lo, Jim O’Brien and Eric Rosengren. Furthermore, we are grateful for comments we received at the 2004 European Finance Association Meetings in Maastricht, in particular by our discussant Marco da Rin and by Christian Upper, at the 2004 Ottobeuren seminar in economics, notably the thoughts of our discussant Ernst Baltensberger, of Friedrich Heinemann and of Gerhard Illing, as well as at seminars of the Max Planck Institute for Research on Collective Goods, the Federal Reserve Bank of St. Louis, the ECB and the University of Frankfurt. Gabe de Bondt and David Marques Ibanez supported us enormously in finding yield spread data, Lieven Baele and Richard Stehle kindly made us aware of pitfalls in Datastream equity data. Very helpful research assistance by Sandrine Corvoisier, Peter Galos and Marco Lo Duca as well as editorial support by Sabine Wiedemann are gratefully acknowledged. Any views expressed only reflect those of the authors and should not be interpreted as the ones of the ECB or the Eurosystem. The views expressed herein are those of the author(s) and do not necessarily reflect the views of the National Bureau of Economic Research. This paper derives indicators of the severity and structure of banking system risk from asymptotic interdependencies between banks’ equity prices. We use new tools available from multivariate extreme value theory to estimate individual banks’ exposure to each other (“contagion risk”) and to systematic risk. Moreover, by applying structural break tests to those measures we study whether capital markets indicate changes in the importance of systemic risk over time. Using data for the United States and the euro area, we can also compare banking system stability between the two largest economies in the world. Finally, for Europe we assess the relative importance of cross-border bank spillovers as compared to domestic bank spillovers. The results suggest, inter alia, that systemic risk in the US is higher than in the euro area, mainly as cross-border risks are still relatively mild in Europe. On both sides of the Atlantic systemic risk has increased during the 1990s

Large Swings in Currencies driven by Fundamentals

Exchange rate returns are fat-tailed distributed. We provide evidence that the apparent non-normality derives from the behavior of macroeconomic fundamentals. Economic and probabilistic arguments are offered for such a relationship. Empirical support is given by testing against normality and through investigating the tail shapes of the fundamentals' distributions. The currently available data sets on floating exchange rates permit a clearer picture than the relatively short spans with macroeconomic data available previously

Dom Stabiliteitspact

Aanvankelijk vervulde het Stabiliteitspact een nuttige functie: duidelijke regels waarborgden de monetaire integratie. Door de vergrijzing en de conjuncturele verslechtering is het Pact aan herziening toe. Meer ruimte voor stabilisatiebeleid en het mede beschouwen van de pensioensituatie zijn belangrijker dan strikte naleving van het Pact omwille van geloofwaardigheid

Fixing soft margins

Non-parametric tolerance limits are employed to calculate soft margins such as advocated in Williamson's target zone proposal. In particular, the tradeoff between softness and zone width is quantified. This may be helpful in choosing appropriate margins. Furthermore, it offers policymakers a framework for reference in the case of changing exchange rate policy. The empirical applications include an evaluation of the EMS zone width. We also show that the procedures for calculating the soft margins are robust against alternative data-generating mechanisms

Permeable Surface Corrections for Ffowcs Williams and Hawkings Integrals

The acoustic prediction methodology discussed herein applies an acoustic analogy to calculate the sound generated by sources in an aerodynamic simulation. Sound is propagated from the computed flow field by integrating the Ffowcs Williams and Hawkings equation on a suitable control surface. Previous research suggests that, for some applications, the integration surface must be placed away from the solid surface to incorporate source contributions from within the flow volume. As such, the fluid mechanisms in the input flow field that contribute to the far-field noise are accounted for by their mathematical projection as a distribution of source terms on a permeable surface. The passage of nonacoustic disturbances through such an integration surface can result in significant error in an acoustic calculation. A correction for the error is derived in the frequency domain using a frozen gust assumption. The correction is found to work reasonably well in several test cases where the error is a small fraction of the actual radiated noise. However, satisfactory agreement has not been obtained between noise predictions using the solution from a three-dimensional, detached-eddy simulation of flow over a cylinder

Physics Potential of Very Intense Conventional Neutrino Beams

The physics potential of high intensity conventional beams is explored. We consider a low energy super beam which could be produced by a proposed new accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil scintillator detectors are studied as possible candidates for a neutrino oscillation experiment which could improve our current knowledge of the atmospheric parameters and measure or severely constrain the parameter connecting the atmospheric and solar realms. It is also shown that a very large water detector could eventually observe leptonic CP violation. The reach of such an experiment to the neutrino mixing parameters would lie in-between the next generation of neutrino experiments (MINOS, OPERA, etc) and a future neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice, March, 200

A study of atmospheric neutrinos with the IMB detector

A sample of 401 contained neutrino interactions collected in the 3300 metric ton fiducial mass IMB detector was used to study neutrino oscillations, geomagnetic modulation of the flux and to search for point sources. The majority of these events are attributed to neutrino interactions. For the most part, these neutrinos are believed to originate as tertiary products of cosmic ray interactions in the atmosphere. The neutrinos are a mixture of v sub e and v sub micron

Analytic Results for the Gravitational Radiation from a Class of Cosmic String Loops

Cosmic string loops are defined by a pair of periodic functions ${\bf a}$ and ${\bf b}$, which trace out unit-length closed curves in three-dimensional space. We consider a particular class of loops, for which ${\bf a}$ lies along a line and ${\bf b}$ lies in the plane orthogonal to that line. For this class of cosmic string loops one may give a simple analytic expression for the power $\gamma$ radiated in gravitational waves. We evaluate $\gamma$ exactly in closed form for several special cases: (1) ${\bf b}$ a circle traversed $M$ times; (2) ${\bf b}$ a regular polygon with $N$ sides and interior vertex angle $\pi-2\pi M/N$; (3) ${\bf b}$ an isosceles triangle with semi-angle $\theta$. We prove that case (1) with $M=1$ is the absolute minimum of $\gamma$ within our special class of loops, and identify all the stationary points of $\gamma$ in this class.Comment: 15 pages, RevTex 3.0, 7 figures available via anonymous ftp from directory pub/pcasper at alpha1.csd.uwm.edu, WISC-MILW-94-TH-1