The Failed Experiment: Gun Control and Public Safety in Canada, Australia, England and Wales

Widely televised firearm murders in many countries during the 20th Century have spurred politicians to introduce restrictive gun laws. The politicians then promise that the new restrictions will reduce criminal violence and "create a safer society." It is time to pause and ask if gun laws actually do reduce criminal violence. Gun laws must be demonstrated to cut violent crime or gun control is no more than a hollow promise. What makes gun control so compelling for many is the belief that violent crime is driven by the availability of guns and, more importantly, that criminal violence in general may be reduced by limiting access to firearms. In this study, I examine crime trends in Commonwealth countries that have recently introduced firearm regulations: i.e., Great Britain, Australia, and Canada. The widely ignored key to evaluating firearm regulations is to examine trends in total violent crime, not just firearms crime. Since firearms are only a small fraction of criminal violence, the public would not be safer if the new law could reduce firearm violence but had no effect on total criminal violence. The upshot is that violent crime rates, and homicide rates in particular, have been falling in the United States, but increasing in Canada, Australia, and the United Kingdom. The drop in the American crime rate is even more impressive when compared with the rest of the world. In 18 of the 25 countries surveyed by the British Home Office, violent crime increased during the 1990s. This contrast should provoke thinking people to wonder what happened in those countries where they introduced increasingly restrictive firearm laws

Physics behind the minimum of relative entropy measures for correlations

The relative entropy of a correlated state and an uncorrelated reference state is a reasonable measure for the degree of correlations. A key question is however which uncorrelated state to compare to. The relative entropy becomes minimal for the uncorrelated reference state that has the same one-particle density matrix as the correlated state. Hence, this particular measure, coined nonfreeness, is unique and reasonable. We demonstrate that for relevant physical situations, such as finite temperatures or a correlation enhanced orbital splitting, other choices of the uncorrelated state, even educated guesses, overestimate correlations.Comment: 4 pages, 1 figure, final version as to appear European Physical Journal

L2L^2 Analysis of the Multi-Configuration Time-Dependent Hartree-Fock Equations

The multiconfiguration methods are widely used by quantum physicists and chemists for numerical approximation of the many electron Schr\"odinger equation. Recently, first mathematically rigorous results were obtained on the time-dependent models, e.g. short-in-time well-posedness in the Sobolev space $H^2$ for bounded interactions (C. Lubichand O. Koch} with initial data in $H^2$, in the energy space for Coulomb interactions with initial data in the same space (Trabelsi, Bardos et al.}, as well as global well-posedness under a sufficient condition on the energy of the initial data (Bardos et al.). The present contribution extends the analysis by setting an $L^2$ theory for the MCTDHF for general interactions including the Coulomb case. This kind of results is also the theoretical foundation of ad-hoc methods used in numerical calculation when modification ("regularization") of the density matrix destroys the conservation of energy property, but keeps invariant the mass.Comment: This work was supported by the Viennese Science Foundation (WWTF) via the project "TDDFT" (MA-45), the Austrian Science Foundation (FWF) via the Wissenschaftkolleg "Differential equations" (W17) and the START Project (Y-137-TEC) and the EU funded Marie Curie Early Stage Training Site DEASE (MEST-CT-2005-021122

Would banning firearms reduce murder and suicide? A review of international evidence

The world abounds in instruments with which people can kill each other. Is the widespread availability of one of these instruments, firearms, a crucial determinant of the incidence of murder? Or do patterns of murder and/or violent crime reflect basic socio-economic and/or cultural factors to which the mere availability of one particular form of weaponry is irrelevant? This article examines a broad range of international data that bear on the question whether widespread firearm access is an important contributing factor in murder and/or suicide. Our conclusion from the available data is that suicide, murder and violent crime rates are determined by basic social, economic and/or cultural factors with the availability of any particular one of the world's myriad deadly instrument being irrelevant

Design and implementation of the land surface model NaturalEnvironment within the generic framework OpenDanubia for integrative, distributed environmental modelling

The project GLOWA-Danube (http://www.glowa-danube.de) aimed at investigating the manifold consequences of Global Change on regional water resources in the Upper Danube Basin. In order to achieve this task, an interdisciplinary, university-based network of experts developed the integrative Decision Support System OpenDanubia (OD). The common base for implementing and coupling the various scientific model components is a generic framework, which provides the coordination of the coupled models that run in parallel exchanging iteratively data via their interfaces. The OD framework takes care of technical aspects, such as ordered data exchange between sub-models, data aggregation, data output, model parallelization and data distribution over the network, which means that model developers do not have to be concerned about complexities evolving from coupling their models. Within this framework the sub-model NaturalEnvironment, representing a land surface model, was developed and implemented. The object-oriented design of this sub-model facilitates a plain, logical representation of the actual physical processes simulated by the sub-model. Physical processes to be modelled are organized in naturally ordered, exchangeable lists that are executed on each spatial computation unit for each modelling time step, depending on their land cover. The type of land cover to be simulated on each freely defined spatial unit is distinguished by one of the three types aquatic, terrestrial and glacier. Additionally, the type terrestrial is influenced by dynamic land use changes which can be triggered e.g. by the socio-economic OD sub-model Farming. This paper presents the basic design of the open source (GPL'ed) OD framework and highlights the implementation of the sub-model NaturalEnvironment within this framework, as well as its interactions with other components included in OD