Probability distributions and Gleason's Theorem

We discuss concrete examples for frame functions and their associated density operators, as well as for non-Gleason type probability measures.Comment: Presented at the 4th conference on Foundations of Probability and Physics, held in Vaexjoe, June 4-9, 200

Zero-sum Risk-Sensitive Stochastic Games

In this paper we consider two-person zero-sum risk-sensitive stochastic dynamic games with Borel state and action spaces and bounded reward. The term risk-sensitive refers to the fact that instead of the usual risk neutral optimization criterion we consider the exponential certainty equivalent. The discounted reward case on a finite and an infinite time horizon is considered, as well as the ergodic reward case. Under continuity and compactness conditions we prove that the value of the game exists and solves the Shapley equation and we show the existence of optimal (non-stationary) strategies. In the ergodic reward case we work with a local minorization property and a Lyapunov condition and show that the value of the game solves the Poisson equation. Moreover, we prove the existence of optimal stationary strategies. A simple example highlights the influence of the risk-sensitivity parameter. Our results generalize findings in Basu/Ghosh 2014 and answer an open question posed there

Runge-Kutta convolution quadrature and FEM-BEM coupling for the time dependent linear Schr\"odinger equation

We propose a numerical scheme to solve the time dependent linear Schr\"odinger equation. The discretization is carried out by combining a Runge-Kutta time-stepping scheme with a finite element discretization in space. Since the Schr\"odinger equation is posed on the whole space $\R^d$ we combine the interior finite element discretization with a convolution quadrature based boundary element discretization. In this paper we analyze the resulting fully discrete scheme in terms of stability and convergence rate. Numerical experiments confirm the theoretical findings

Endogenous adjusted Output Quotas - The Abolishment of the Raw Milk Quota in the European Union

This paper discusses an approach to implement output quotas in the GTAP model which permits an endogenous adjustment of both the supplied quantity and the quota rent. Since the quota rent is interpreted as additional earnings of the factors used no change of the worldwide GTAP data base is required. Several modifications of the GTAP model and two exogenous coefficients are necessary. Considering uncertain values of one of the coefficients, systematic sensitivity analysis is applied. The abolishment of the raw milk quota in the European Union would lead to a remarkable decrease in raw milk prices in most member countries. The raw milk production increases in Denmark, Ireland, Luxembourg and the Netherlands while it declines in Greece and Portugal. In the other member countries the raw milk production changes slightly.general equilibrium model, GTAP, output quota, raw milk production, sensitivity analysis, Agribusiness,

Brownian scattering of a spinon in a Luttinger liquid

We consider strongly interacting one-dimensional electron liquids where elementary excitations carry either spin or charge. At small temperatures a spinon created at the bottom of its band scatters off low-energy spin- and charge-excitations and follows the diffusive motion of a Brownian particle in momentum space. We calculate the mobility characterizing these processes, and show that the resulting diffusion coefficient of the spinon is parametrically enhanced at low temperatures compared to that of a mobile impurity in a spinless Luttinger liquid. We briefly discuss that this hints at the relevance of spin in the process of equilibration of strongly interacting one-dimensional electrons, and comment on implications for transport in clean single channel quantum wires

A small-scale dynamo in feedback-dominated galaxies - III. Cosmological simulations

Magnetic fields are widely observed in the Universe in virtually all astrophysical objects, from individual stars to entire galaxies, even in the intergalactic medium, but their specific generation has long been debated. Due to the development of more realistic models of galaxy formation, viable scenarios are emerging to explain cosmic magnetism, thanks to both deeper observations and more efficient and accurate computer simulations. We present here a new cosmological high-resolution zoom-in magnetohydrodynamic (MHD) simulation, using the adaptive mesh refinement (AMR) technique, of a dwarf galaxy with an initially weak and uniform magnetic seed field that is amplified by a small-scale dynamo driven by supernova-induced turbulence. As first structures form from the gravitational collapse of small density fluctuations, the frozen-in magnetic field separates from the cosmic expansion and grows through compression. In a second step, star formation sets in and establishes a strong galactic fountain, self-regulated by supernova explosions. Inside the galaxy, the interstellar medium becomes highly turbulent, dominated by strong supersonic shocks, as demonstrated by the spectral analysis of the gas kinetic energy. In this turbulent environment, the magnetic field is quickly amplified via a small-scale dynamo process and is finally carried out into the circumgalactic medium by a galactic wind. This realistic cosmological simulation explains how initially weak magnetic seed fields can be amplified quickly in early, feedback-dominated galaxies, and predicts, as a consequence of the small scale dynamo process, that high-redshift magnetic fields are likely to be dominated by their small scale components.Comment: 6 pages, 6 figures, submitted to MNRA

The Impact of education and mismatch on wages: Germany, 1984-2000

In analysing the impact of education on wage differentials and wage growth, we use next to personal characteristics (e. g. education and experience) also jobcharacteristics (e. g. skills required) to explain wages. We estimate wage equations on individual data for Germany, 1984 – 2000. When discussing observed andpreviously unobserved heterogeneity it turns out that personal characteristics like education and experience explain about half of the variation in wages. At least 20 per cent is explained by variation in job characteristics. When comparing the results with similar research for the Netherlands an the USA, the returns toexperience are the same in all countries, while the premiums on required skills and in particular education are much higher in the USA.labour economics ;

Who Replaces Agriculture's Contribution to Settlement in Lagging Rural Areas? An Integrated Input-Output and Dynamic Simulation Analysis

This paper develops an integrated model for analysing regional economic development and structural change in agriculture. The input-output method allows the detailed description of a regional economy. Based on this description, regional growth pole sectors can be identified that are potential leverage points for growth oriented development strategies. Dynamic simulation tests the long term effects of such a development strategy. Model results show that external demand is the main driving force behind regional economic growth. However, development strategies for lagging rural areas have to be coupled to development strategies for regional centres. Only if the rural areas surrounding regional centres become an important asset for the development of these centres can rural areas be stabilised.rural regions, economic development, input-output, dynamic simulation, Community/Rural/Urban Development, C6, R11, R15, R23, R58,