On the discrete spectrum of spin-orbit Hamiltonians with singular interactions

We give a variational proof of the existence of infinitely many bound states below the continuous spectrum for spin-orbit Hamiltonians (including the Rashba and Dresselhaus cases) perturbed by measure potentials thus extending the results of J.Bruening, V.Geyler, K.Pankrashkin: J. Phys. A 40 (2007) F113--F117.Comment: 10 pages; to appear in Russian Journal of Mathematical Physics (memorial volume in honor of Vladimir Geyler). Results improved in this versio

Prognose der jährlichen Leistungsentwicklung im Krankenhaus unter DRG-Bedingungen

Seit Einführung eines fallpauschalierten Vergütungssystems zur Abrechnung vollstationärer Leistungen im Krankenhaus gewinnt die Leistungsplanung im Krankenhaus bei den jährlichen Leistungs- und Entgeltverhandlungen mit den Kostenträgern immer mehr an Bedeutung; diese ist valide letztlich nur durch die enge Abstimmung zwischen den klinisch tätigen Ärzten und dem Krankenhausmanagement möglich. Bei der Leistungsplanung spielt die Prognose von Leistungen eine entscheidende Rolle. Im Rahmen dieser Arbeit erfolgte die Entwicklung eines Modells zur Prognose der Leistungsentwicklung im Krankenhaus auf Grundlage periodenbezogener Leistungsdaten (Casemix) des Universitätsklinikums Münster im Zeitraum Juli 2006 bis Juni 2008. Dabei wurden neben „fertigen Leistungen“, d.h. Behandlungsfällen, die bereits entlassen und abgerechnet wurden, auch „unfertige Leistungen“, d.h. Leistungen, die bereits erbracht, aber noch nicht abgerechnet werden konnten, da die Behandlungsfälle noch nicht aus dem Krankenhaus entlassen wurden, berücksichtigt

Hector, a fast simulator for the transport of particles in beamlines

Computing the trajectories of particles in generic beamlines is an important ingredient of experimental particle physics, in particular regarding near-beam detectors. A new tool, Hector, has been built for such calculations, using the transfer matrix approach and energy corrections. The limiting aperture effects are also taken into account. As an illustration, the tool was used to simulate the LHC beamlines, in particular around the high luminosity interaction points (IPs), and validated with results of the Mad-X simulator. The LHC beam profiles, trajectories and beta functions are presented. Assuming certain forward proton detector scenarios around the IP5, acceptance plots, irradiation doses and chromaticity grids are produced. Furthermore, the reconstruction of proton kinematic variables at the IP (energy and angle) is studied as well as the impact of the misalignment of beamline elements.Comment: 40 pages, 20 figures; added references, corrected typos ; submitted to JINS

Approximation by point potentials in a magnetic field

We discuss magnetic Schrodinger operators perturbed by measures from the generalized Kato class. Using an explicit Krein-like formula for their resolvent, we prove that these operators can be approximated in the strong resolvent sense by magnetic Schrodinger operators with point potentials. Since the spectral problem of the latter operators is solvable, one in fact gets an alternative way to calculate discrete spectra; we illustrate it by numerical calculations in the case when the potential is supported by a circle.Comment: 16 pages, 2 eps figures, submitted to J. Phys.

Parametrizations of density matrices

This article gives a brief overview of some recent progress in the characterization and parametrization of density matrices of finite dimensional systems. We discuss in some detail the Bloch-vector and Jarlskog parametrizations and mention briefly the coset parametrization. As applications of the Bloch parametrization we discuss the trace invariants for the case of time dependent Hamiltonians and in some detail the dynamics of three-level systems. Furthermore, the Bloch vector of two-qubit systems as well as the use of the polarization operator basis is indicated. As the main application of the Jarlskog parametrization we construct density matrices for composite systems. In addition, some recent related articles are mentioned without further discussion.Comment: 31 pages. v2: 32 pages, Abstract and Introduction rewritten and Conclusion section added, references adde