Thermal and Dynamical Particle Creation in a Curved Geometry

A generalization of ``Termo Field Dynamics'' to a curved geometry is proposed. In particular a neutral scalar field minimally coupled to gravity is considered as matter content in a Robertson-Walker metric. A non linear amplification in the particle creation is obtained, due to the altogether action of thermal and geometric effects. As a consequence the frequencies in the system look like red shifted with respect to the case where the thermal creation is not taken into account.Comment: 13 page

Urban Multifunctional Land Use: Theoretical and Empirical Insights on Economies of Scale, Scope and Diversity

A recent planning device aimed at dealing with land scarcity is the propagation of multifunctional land use. This paper describes the evolution of urban planning concepts and their links to economic theory. We argue that the most distinctive feature of multifunctional land use is its emphasis on return to diversity. This concept is rooted in the modern economic theory of agglomeration. Empirical evidence is shown to provide some support for the quantitative relevance of return to diversity, but is still to a large extent in its infancy. More evidence is required for policy purposes aimed at identifying the optimal extent to which multifunctional land use projects have to be pursued

The impact of 'incubator' organizations on opportunity recognition and technology innovation in new, entrepreneurial high-technology ventures

The increasingly important role of SMEs in both regional and national economic development has been widely acknowledged in the economic and entrepreneurship literature.The development of an economic and policy environment supporting new, high-growth, high-technology ventures has become common strategy adopted by many policy makers, as a critical means of promoting future economic growth and job creation. Many of these high-technology, economic development programmes embrace enabling technologies, such as micro- and nanotechnology- based firms.Although nascent entrepreneurs have numerous sources of advice and support as they embark on the venture creation pathway, aspects of an entrepreneur's past and present experience exert a central and often pivotal influence on their ability to engage effectively in opportunity recognition and exploitation of innovative new product technologies.This article argues that the professional/social environment in which an entrepreneur lives and works has a fundamental impact upon their ability to recognize and exploit opportunities.The work explores the innovation process in young high-technology firms and focuses upon the long-term impact of previous employment, in 'incubator' organizations, in influencing opportunity recognition and product innovation processes. Findings suggests that incubator organizations fundamentally shape entrepreneurs' technical and commercial experience of markets, strongly influence their attitudes to risk and personal achievement, help develop an intricate network of social capital and resources and, finally, provide critical knowledge of the existence, availability and applicability of technology solutions in new and emerging markets. Issues are explored through in-depth interviews in 31 companies in Aberdeen, Scotland, and Ottawa, Canada, cities with established strengths in technology development in academic, commercial and government research organizations, and a history of successful high-technology firm creation. Implications for theory and policy are discussed, with particular reference to the lessons to be learned to assist the development of sectors based upon newly emerging technologies