Nonlinear Properties of Vielbein Massive Gravity

We propose a non-linear extension of the Fierz-Pauli mass for the graviton through a functional of the vielbein and an external Minkowski background. The functional generalizes the notion of the measure, since it reduces to a cosmological constant if the external background is formally sent to zero. Such a term and the explicit external background, emerge dynamically from a bi--gravity theory, having both a massless and a massive graviton in its spectrum, in a specific limit in which the massless mode decouples, while the massive one couples universally to matter. We investigate the massive theory using the Stueckelberg method and providing a 't Hooft-Feynman gauge fixing in which the tensor, vector and scalar Stueckelberg fields decouple. We show that this model has the softest possible ultraviolet behavior which can be expected from any generic (Lorentz invariant) theory of massive gravity, namely that it becomes strong only at the scale Lambda_3 = (m_g^2 M_P)^{1/3}.Comment: 23+1 pages LaTeX, 3 figures, few typos correcte

Medicine and tourism as agents of medical tourism

© 2020, Advanced Scientific Research. All rights reserved. In article approaches to studying medical tourism are considered. On the basis of the analysis the conclusion is drawn that, despite the main mission of medical tourism as instrument of improvement of the population, his key agent is the tourist market. This segment of the market is capable to organize a travel to the vacation spot and to provide necessary service, and receiving medical services predetermines only the purpose and can influence the choice of the vacation spot. Scientists in the field of tourism, health care and economy consider medical tourism one of the most perspective types of the industry in the 21st century that causes development of medicine, improvement of quality of the provided medical services, improvement of efficiency of health care systems, development of the sphere of tourism and the industries accompanying it, increase in a contribution to GDP of the region/country

The effective use of heritage sites of the major sporting events in Russia

This article dwells on the positive and negative experience of using facilities remaining after the major sporting events in the country. The authors analyse the use of stadiums built for the FIFA World Cup, as well as the facilities of Kazan involved during the Universiade 2013. The research resulted in the conclusion about the necessity as far back at the designing stage to study both the relevancy of the sporting venue during the event and its potential usage afterwards. The authors make a point that there is a positive emotional effect, which is revealed in the growth of tourism, and increasing the attractiveness of the territory for local residents. The results obtained can be useful for cities and countries that have yet to host major sports events