There appears to be three, perhaps related, ways of approaching the nature of vacuum energy . The first is to say that it is just the lowest energy state of a given, usually quantum, system. The second is to equate vacuum energy with the Casimir energy. The third is to note that an energy difference from a complete vacuum might have some long range effect, typically this energy difference is in...

This is a short review of different approaches in the study of magnetic curves for a certain magnetic field and on the fixed energy level. We emphasize them in the case when the magnetic trajectory corresponds to a Killing vector field associated to a screw motion in the Euclidean 3-space.

We explore how general economic conditions impact defaults and major credit rating changes by fitting reduced-form Cox intensity models with a broad range of macroeconomic and firm-specific ratings-related variables. For all corporate issuers in the period 1981 2002 we find both types of factors strongly influenced the risk of a credit event. However, while the effects of ratings-related factor...

We consider the analytic properties of Bioch Hamiltonians and their energy levels as functions of quasi-momentum k. Among other results are: (1) The only entire band is the trivial free electron parabola. (2) The only isolated singularities allowed are branch points. (3) In one dimension, no natural boundaries or logarithmic branch points occur. (4) The periodic attractive screened Coulomb latt...

We study the binding energy and the width of the Θ in nuclei, associated to the KN and KπN components. The first one leads to negligible contributions while the second one leads to a sizeable attraction, enough to bind the Θ in nuclei. Pauli blocking and binding effects on the KN decay reduce considerably the Θ decay width in nuclei and medium effects associated to the KπN component also lead t...

The presently applied method of mining reconnaissance used for the designing of mining works in areas subject to seismic hazards is often providing erroneous read-outs involving the states of potential rockburst hazards. It results from the fact that a number of factors characterizing the influence of mining works on the stress-energy state of rockmass are not taken into consideration. In the p...

Pulmonary embolism is a common condition with high short– term morbidity. Pulmonary embolism can be treated successfully but diagnosis remains difficult due to the large variability of symptoms, which are often non–specific including breath shortness, chest pain and cough. Dual energy CT produces 4–dimensional data by acquiring variation of attenuation with respect to spatial coordinates and al...

This paper uses a software technology approach to tackle the problem of complexity control. A multiplicity of system models, abstraction levels and development primitives are employed, with special attention paid to the use of relationship in the tackling process. The paper explains the steps needed to locate the balance point between competing factors in the search of the final equilibrium sta...

The Dirac equation in a chromomagnetic field is solved for colored particle moving in a limited space volume. Quantized energy levels and the corresponding wave functions are found for backgrounds both directed along third axes and having spherical symmetry. It was shown interrelation with the case of motion in an infinite space volume.