Cheeger's energy on the Harmonic Sierpinski Gasket

Koskela and Zhou have proven that, on the harmonic Sierpinski gasket with Kusuoka's measure, the "natural" Dirichlet form coincides with Cheeger's energy. We give a different proof of this result, which uses the properties of the Lyapounov exponent of the gasket

Decays of the f0(1370) scalar glueball candidate in pp Central Exclusive Production (CEP) and in antiproton annihilations at rest

Decays into two charged pions of the f0(1370) are the main source of an isolated structure localized between 1.2 and 1.5 GeV in the two charged pions mass spectrum measured in pp Central Exclusive Production (CEP) at 200 GeV at very low four momentum transfer ltl by the STAR experiment. These data confirm in the two charged pions decay channel the existence of the f0(1370) as an isolated well identified structure previously observed in K+K-, KsKs, 4 charged pions, two charged and two neutral pions and 4 neutral pions decays measured in antiproton annihilations at rest. The ensemble of these data point at a high gluon content of the f0(1370). CEP interactions at higher energies favour production of 0++ and 2++ mesons. Selection of events with lower ltl at both proton vertices suppresses 2++ structures. LHC runs dedicated to pp CEP measurements at low ltl could then provide a unique source of all the low energy scalars. This would make it clear if and where scalar gluonium is resident and the nature (composition in terms of quarks, antiquarks and gluons) of f0(500), f0(980), f0(1370), f0(1500) and f0(1710).Comment: 8 pages, 5 figures, presented at QCD@Work-International Workshop on QCD Theory and Experiment, 25-28 June 2018, Matera, Italy (to be published in Proceedings). arXiv admin note: text overlap with arXiv:1809.0449

Why do scientists create academic spin-offs? The influence of the context

The aim of this work is to examine the nature of academic spin-offs in a specific context: the Emilia-Romagna region (Italy). More specifically we investigate the individual reasons as to explain why scientists create academic spin-offs and how the creation process unfolds. Most economics and management literature on the topic considers the technological characteristics of such a choice, although recently the individual motivations behind the creation of such ventures have been investigated. However, less attention has been paid to the social and contextual dimensions of the matter. This study relates contextual characteristics to individual motivation. In particular it is argued that the funding constraints of the Italian academic environment, the low level of demand for doctorate holders within the Italian public and private sectors and the presence of favourable supporting policy tools in the region analysed, play a fundamental role in shaping the individual motivation of scientists in choosing this option. By way of a multiple case study research this work provides evidence that the academic spin-off in Emilia-Romagna is, for young scientists, a way to escape the bottlenecks of the Italian academic system allowing them to work in their field of expertise. This paper builds on the research regarding individual reasoning underlying personal decisions to create an academic spin-off and the need to analyse the phenomenon in relation to its context. Finally some policy implications are put forth

Innovation Diffusion and the Evolution of Regional Disparities

An important part of modern theory on regional disparities identifies in the innovative activities the source of competitive advantage and, consequently, of the observed differences in economic development. However, since differently from a standard physical factor of production, knowledge can be used in many different places and many productions at the same time, innovation is the basic but not the only feature of the process: an essential role is also played by imitation, the acquisition of external knowledge through devoted efforts, and diffusion, the non costly acquisition of external knowledge. If, for example, the diffusion of technology were instantaneous and not protected by any form of patenting, the physical place in which innovation takes place would be irrelevant. Since knowledge is instead 'sticky', the innovative region get an advantage, but the extent of this advantage still depends on the easiness of diffusion. This mechanism of knowledge creation and diffusion has been affected by two important changes: the first one is the ‘technological revolution’, as some scholars called the process that, in the past century, changed innovation from being the outcome of initiatives of single entrepreneurs, to the outcome of specifically designed R&D departments of the firms; this has determined an increase in the innovation pace. The second change is the recent fast development of new means of communications, called ICTs, which have made easier, faster and cheaper the transfer of blueprinted knowledge across places. This is determining an increase in the speed of diffusion of knowledge, even if, in order to use it, it is always necessary to have people able to understand and implement it. This article investigates the effect that the interaction between the creation and the diffusion of technology brings on regional disparities. We will show that an increase in the pace of innovation, as the one that took place in the XXth century, can engender regional income disparities; we will also show that if, afterwards, the speed of diffusion also increases enough, these disparities can fade out. We will not, at this stage, guess which effect will prevail. To analyse the problem, we will first build a simple model with technological disparities as the source of income disparities and a set up aimed at representing all knowledge flows. The basic model will then be used in two different ways for the study of innovation and diffusion mechanisms. We will show that the most important variable to determine if income disparities exist is the ratio between the speed of diffusion and the speed of innovation. In particular, when this ratio is low, the most likely prediction is an equilibrium with both technological and income disparities. For intermediate values, technological disparities will exist, but will not be large enough to generate income disparities; for higher values, there will not be technological disparities anymore and, consequently, no income disparities.

Equilibrium policy simulations with random utility models of labour supply

Many microeconometric models of discrete labour supply include alternative-specific constants meant to account for (possibly besides other factors) the density or accessibility of particular types of jobs (e.g. parttime jobs vs. full-time jobs). The most common use of these models is the simulation of tax-transfer reforms. The simulation is usually interpreted as a comparative static exercise, i.e. the comparison of different equilibria induced by different policy regimes. The simulation procedure, however, typically keeps fixed the estimated alternative-specific constants. In this note we argue that this procedure is not consistent with the comparative statics interpretation. Equilibrium means that the number of people willing to work on the various job types must be equal to the number of available jobs. Since the constants reflect the number of jobs and since the number of people willing to work change as a response to the change in tax-transfer regime, it follows that the constants should also change. A structural interpretation of the alternative-specific constants leads to the development of a simulation procedure consistent with the comparative static interpretation. The procedure is illustrated with an empirical example.Random Utility; Discrete Choice; Labour Supply; Simulation of tax reforms; Alternative-specific constants; Equilibrium simulation

The Governance of Knowledge in Academic Spin-Offs. The Case of Emilia-Romagna.

The phenomenon of academic spin-offs (ASOs) has been widely studied in recent times. Scholars have mainly concentrated on identifying the factors that favours the phenomenon and the incentive alignments of the parties involved in the process. These works tend to remain static in nature by solely investigating the ex ante determinants of the process, that is the elements that favoured a context to be more profitable than others, usually in terms of the number of ASOs generated. More recently scholars have also acknowledged that ASOs are heterogeneous firms and have started investigating the development process of such firms. It has been highlighted that ASOs need to overcome certain defined stage of growth in order to become established firms in the market. Our work continues this line of investigation and aims to gives evidence that the paths of ASO development are heterogeneous themselves. We investigate the flows of knowledge taking place within and across the firm in a dynamic manner, at various stage of the development process of the firm: we study the governance of knowledge in a sub-population of ASOs and give evidence of the variety of possible ways the firm can develop.governance of knowledge; academic spin-off; theory of the firm; technology development

Regional Economies, Innovation and Competitiveness in a System Dynamics Representation

The System Dynamics methodology is used in this article as unifying approach in order to show how a number of theories about the performance of territories developed in the past 20 years can integrate the one with the other; to demonstrate this, a model of local economy coherent with these schools is constructed and simulated. According to these theories, the ability to produce and use knowledge is at the centre of regional competitiveness in the advanced world; the model and the paper illustrate the elements of the local economic system and how they have to work coherently towards the continuous process of innovation, needed to be successful. The model also shows in a new framework how, due to the cumulative nature of this innovation process, it is possible to obtain equilibria with regional income differentiation, even in the presence of identical territories. When this is the case, structural policies, aiming to allow lagging regions to better innovate and/or imitate external knowledge, are appropriate.