On Y. Nievergelt's Inversion Formula for the Radon Transform

Mathematics Subject Classification 2010: 42C40, 44A12.In 1986 Y. Nievergelt suggested a simple formula which allows to reconstruct a continuous compactly supported function on the 2-plane from its Radon transform. This formula falls into the scope of the classical convolution-backprojection method. We show that elementary tools of fractional calculus can be used to obtain more general inversion formulas for the k-plane Radon transform of continuous and L^p functions on R^n for all 1 ≤ k < n. Further generalizations and open problems are discussed

Spatial Degrees of Freedom in Everett Quantum Mechanics

Stapp claims that, when spatial degrees of freedom are taken into account, Everett quantum mechanics is ambiguous due to a "core basis problem." To examine an aspect of this claim I generalize the ideal measurement model to include translational degrees of freedom for both the measured system and the measuring apparatus. Analysis of this generalized model using the Everett interpretation in the Heisenberg picture shows that it makes unambiguous predictions for the possible results of measurements and their respective probabilities. The presence of translational degrees of freedom for the measuring apparatus affects the probabilities of measurement outcomes in the same way that a mixed state for the measured system would. Examination of a measurement scenario involving several observers illustrates the consistency of the model with perceived spatial localization of the measuring apparatus.Comment: 34 pp., no figs. Introduction, discussion revised. Material tangential to main point remove

Global monopole, dark matter and scalar tensor theory

In this article, we discuss the space-time of a global monopole field as a candidate for galactic dark matter in the context of scalar tensor theory.Comment: 8 pages, Accepted in Mod. Phys. Lett.

Mutual insurance of transport infrastructure construction risks as an inherent part of competitive environment

In this article we introduce mutual insurance as an inherent part of competitive environment in the field of insurance of the transport infrastructure construction risks. The competitive environment makes a great impact on the market behavior of the actors. The monopolization creates the environment, which does not prevent the negative steps of the firm in different directions. The article shows, that mutual insurance is a significant factor which can prevent the monopolization of the insurance market. This is a specific factor that is inherent only to this kind of the market. The competitive advantages of the mutual insurance organizations, their attractiveness to the clients (the insured) are conditioned with the specific relations between the insured and the insurance organization, such as the decision of the main questions of the financial activity of the insurer on the meeting of all the insured or their representatives, the possibility to insure the risks, which the commercial insurers do not insure and some others.peer-reviewe