An application of the renormalization group to the calculation of the vacuum decay rate in flat and curved space-time

I show that an application of renormalization group arguments may lead to significant corrections to the vacuum decay rate for phase transitions in flat and curved space-time. It can also give some information regarding its dependence on the parameters of the theory, including the cosmological constant in the case of decay in curved space-time.Comment: 10 pages, LaTeX, various comments and references adde

Feynman rules for Gauss's law

I work on a set of Feynman rules that were derived in order to incorporate the constraint of Gauss's law in the perturbation expansion of gauge field theories and calculate the interaction energy of two static sources. The constraint is implemented via a Lagrange multiplier field, $\lambda$, which, in the case of the non-Abelian theory, develops a radiatively generated effective potential term. After analysing the contributions of various solutions for $\lambda$, the confining properties and the various phases of the theory are discussed.Comment: 18 pages, 10 figure

Gravitational effects on critical Q-balls

In a cosmological phase transition in theories that admit Q-balls there is a value of the soliton charge above which the soliton becomes unstable and expands, converting space to the true vacuum, much like a critical bubble in the case of ordinary tunneling. Here I consider the effects of gravity on these solitons and I calculate the lowest gravitational corrections to the critical radius and charge.Comment: LaTeX, 8 pages, final version to appear in EP

CITIES COMPETITION, PLACE MARKETING AND ECONOMIC DEVELOPMENT IN SOUTH EUROPE: THE BARCELONA CASE AS FDI DESTINATION

The aim of the article is to focus on the especially interesting area of South Europe and to present and points out the strategic development process, in one of the most representative examples of its successful implementation, which is the city of Barcelona. Barcelona, which in the last 20 years, managed to increase its competitiveness becoming one of the most attractive investment destinations on international level. The city?s economic dynamism, its strategic position in the South of Europe and a clearly-consolidated international projection have turned the economic area of Barcelona into an international platform of economic activities, a driving force behind development in Southern Europe, especially oriented towards new, emergent, competitive and international sectors with an uninterrupted growth of their foreign markets.Cities competition, economic development, strategic planning, Barcelona.

THE ENTREPRENEURIAL CAPACITY OF LOCAL AUTHORITIES IN SOUTH-EASTERN EUROPE - AN ENTERPRISE PERSPECTIVE

The article is looking into whether the management ability but also the inspection of development policies on the part of local city authorities influences the competitiveness of firms. Origin of this survey has been various approaches of the last decades which point out the significance of entrepreneurial capacity and the ability of local authorities to manage policies on local level. The analysis uses data from 310 small-medium size firms of Southeastern Europe. Through exploratory factor and cluster analysis the article concludes that the ability of Local Authorities to implement development policies, to develop co-operations with the private sector and to manage natural and human resources are important for firm competitiveness. At the same time it brings out the significance of these factors for the respective firms in the wider southeastern zone of Europe.local authorities; firm competitiveness; management and control; cluster analysis; Southeastern Europe

Quantum-classical interactions through the path integral

I consider the case of two interacting scalar fields, \phi and \psi, and use the path integral formalism in order to treat the first classically and the second quantum-mechanically. I derive the Feynman rules and the resulting equation of motion for the classical field, which should be an improvement of the usual semi-classical procedure. As an application I use this method in order to enforce Gauss's law as a classical equation in a non-abelian gauge theory. I argue that the theory is renormalizable and equivalent to the usual Yang-Mills as far as the gauge field terms are concerned. There are additional terms in the effective action that depend on the Lagrange multiplier field \lambda that is used to enforce the constraint. These terms and their relation to the confining properties of the theory are discussed.Comment: 16 pages, LaTeX, 1 fig, final version to appear in PR