The su(1,1) dynamical algebra from the Schr\"odinger ladder operators for N-dimensional systems: hydrogen atom, Mie-type potential, harmonic oscillator and pseudo-harmonic oscillator

We apply the Schr\"odinger factorization to construct the ladder operators for hydrogen atom, Mie-type potential, harmonic oscillator and pseudo-harmonic oscillator in arbitrary dimensions. By generalizing these operators we show that the dynamical algebra for these problems is the $su(1,1)$ Lie algebra.Comment: 10 page

The Effects of Rewards on Tax Compliance Decisions

We analyze how the redistribution of tax revenues influences tax compliance behavior by applying different reward mechanisms. In our experiment, subjects have to make two decisions. In the first stage, subjects decide on the contribution to a public good. In the second stage, subjects declare their income from the first stage for taxation. Our main results are threefold: First, from an aggregated perspective, rewards have a negative overall effect on tax compliance. Second, we observe that rewards affect the decision of taxpayers asymmetrically. In particular, rewards have either no effect (for those who are rewarded) or a negative effect (for those who are not rewarded) on tax compliance. Thus, if a high compliance rate of taxpayers is preferred, rewards should not be used by the tax authority. Third, we find an inverse u-shaped relationship between public good contribution and tax compliance. In particular, up to a certain level, tax compliance increases with subjects' own contributions to the public good. Above this level, however, tax compliance decreases with the public good contribution

Triangleland. II. Quantum Mechanics of Pure Shape

Relational particle models are of value in the absolute versus relative motion debate. They are also analogous to the dynamical formulation of general relativity, and as such are useful for investigating conceptual strategies proposed for resolving the problem of time in quantum general relativity. Moreover, to date there are few explicit examples of these at the quantum level. In this paper I exploit recent geometrical and classical dynamics work to provide such a study based on reduced quantization in the case of pure shape (no scale) in 2-d for 3 particles (triangleland) with multiple harmonic oscillator type potentials. I explore solutions for these making use of exact, asymptotic, perturbative and numerical methods. An analogy to the mathematics of the linear rigid rotor in a background electric field is useful throughout. I argue that further relational models are accessible by the methods used in this paper, and for specific uses of the models covered by this paper in the investigation of the problem of time (and other conceptual and technical issues) in quantum general relativity.Comment: Journal Reference added, minor updates to References and Figure

Characterization of dense zones within the Danian chalks of the Ekofisk Field, Norwegian North Sea

The Ekofisk Field is a giant field which has been producing at a high level for more than forty years and, since 1987, this production has taken place with the support of sea-water injection. The Danian-aged chalk deposits of the Ekofisk Formation and the Maastrichtian Tor Formation form the main reservoir units in the Ekofisk Field. The Ekofisk Formation principally consists of porous resedimented chalks intercalated with relatively thin and lower porosity beds, called dense zones. A multi-scale study of dense zones, from scanning electron microscopy to wells and seismic impedance data, has allowed the characterization and mapping of these deposits. Five main dense zone lithotypes have been identified: (1) argillaceous chalk; (2) chalk with abundant flint nodules; (3) chalk beds cemented with silica/nano-quartz; (4) calcite-cemented chalk; and (5) stylolitized chalk. The different types of dense zones tend to cluster in certain stratigraphic intervals, such as the EE and EM reservoir units at the base and in the middle part of the Ekofisk Formation. Dense zones have different mechanical properties compared to porous chalks and, depending on the connectivity of their fracture networks, they can act as preferential conduits or baffles for the reservoir fluids. An increased understanding of the distribution, characteristics and geological factors at the origin of the dense zones is fundamental to better define the reservoir architecture and ultimately identify unswept zones for future infill drilling targets. © 2013 EAGE/Geological Society of London.status: publishe