Scaling diagram for the localization length at a band edge

A weak-coupling scaling diagram for the Lyapunov exponent and the integrated density of states near a band edge of a random Jacobi matrix is obtained. The analysis is based on the use of a Fokker-Planck operator describing the drift-diffusion of the Pr\"ufer phases

Regulation and competition in German banking: an assessment

In Germany a public discussion on the "power of banks" has been going on for decades now with power having at least two meanings. On the one hand it is the power of banks to control public corporations through direct shareholdings or the exercise of proxy votes - this is the power of banks in corporate control. On the other hand it is market power - due to imperfect competition in markets for financial services - that banks exercise vis-à-vis their loan and deposit customers. In the past, bank regulation has often been blamed to undermine competition and the working of market forces in the financial industry for the sake of soundness and stability of financial services firms. This chapter tries to shed some light on the historical development and current state of bank regulation in Germany. In so doing it tries to embed the analysis of bank regulation into a more general industrial organisation framework. For every regulated industry, competition and regulation are deeply interrelated as most regulatory institutions - even if they do not explicitly address the competitiveness of the market - either affect market structure or conduct. This paper tries to uncover some of the specific relationships between monetary policy, government interference and bank regulation on the one hand and bank market structure and economic performance on the other. In so doing we hope to point to several areas for fruitful research in the future. While our focus is on Germany, some of the questions that we raise and some of our insights might also be applicable to banking systems elsewhere. Revised version forthcoming in "The German Financial System", edited by Jan P. Krahnen and Reinhard H. Schmidt, Oxford University Press

Random Lie group actions on compact manifolds: A perturbative analysis

A random Lie group action on a compact manifold generates a discrete time Markov process. The main object of this paper is the evaluation of associated Birkhoff sums in a regime of weak, but sufficiently effective coupling of the randomness. This effectiveness is expressed in terms of random Lie algebra elements and replaces the transience or Furstenberg's irreducibility hypothesis in related problems. The Birkhoff sum of any given smooth function then turns out to be equal to its integral w.r.t. a unique smooth measure on the manifold up to errors of the order of the coupling constant. Applications to the theory of products of random matrices and a model of a disordered quantum wire are presented.Comment: Published in at http://dx.doi.org/10.1214/10-AOP544 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org

Classification and Redshift Estimation in Multi-Color Surveys

We present a photometric method for identifying stars, galaxies and quasars in multi-color surveys and estimating multi-color redshifts for the extragalactic objects. We use a library of >65000 color templates for comparison with observed objects. The method was originally developed for the Calar Alto Deep Imaging Survey (CADIS), but is now used in a variety of survey projects. We checked its performance by spectroscopy of CADIS objects, where it provides high reliability (6 mistakes among 151 objects with R<24), especially for the quasar selection, and redshifts accurate within sigma_z = 0.03 for galaxies and sigma_z = 0.1 for quasars. For an optimization of future surveys, a few model surveys are compared, which use the same amount of telescope time but different filter sets. In summary, medium-band surveys perform superior to broad-band surveys although they collect less photons. A full account of this work is already in print.Comment: 7 pages, 2 figures, proceedings of MPA/ESO/MPE Joint Astronomy Conference Mining THE SKY held in Garching, Germany, July 31 - Aug 4, 200

They are even larger! More (on) puzzling labor market volatilities

"This paper shows that the German labor market is more volatile than the US labor market at the business cycle frequency. Specifically, the volatility of the cyclical component of several labor market variables (e.g., the job-finding rate, the labor market tightness and vacancies) divided by the volatility of labor productivity is roughly twice as large as in the United States. We derive and simulate a simple model to explain this seemingly puzzling result. This new model provides explanations for this phenomenon, in particular the longer job tenure in Germany." (Author's abstract, IAB-Doku) ((en))Arbeitsmarktindikatoren - internationaler Vergleich, Beschäftigungsschwankung, offene Stellen, Arbeitsproduktivität, Konjunkturabhängigkeit, Betriebszugehörigkeit, Beschäftigungsdauer, Arbeitslosenquote, labour turnover, Kündigung - Quote, Lohnhöhe, institutionelle Faktoren, Lohnfindung, matching - Quote, Produktivitätsentwicklung, USA, Bundesrepublik Deutschland