La cittá, tra conflitto, contraddizioni e progetto

Las ciudades de hoy, impulsoras de la riqueza económica, máximo consumo energético, generadoras de desigualdad social y aislamiento de los individuos, representan el motor de la economía regional, nacional y global. Dependiendo nuestro futuro de estas mismas es necesario dotarnos de nuevos instrumentos de gestión: planes estratégicos, eco balances, balances participativos, sociales para construir un futuro medianamente más deseable. El plan estratégico urbano cultural, reflejo de un modus vivendi, de pensamiento, de trabajo y relación entre los individuos, representa el verdadero catalizador de los nuevos procesos de desarrollo y regeneración económicaToday’s cities, detonators of economic wealth, maximum energy consumption, generators of social inequality and isolation of the individuals, represent the motor of regional, national and global economics. Given that our future depends upon these very cities, it is necessary to have new instruments of management at our disposal: strategic plans, ecobalances, social, participatory and social balances in order to build a future moderately more desirable. The cultural urban strategic plan, a reflection of a modus vivendi, of thought, of work and relation between individuals, represents the true catalyst of the new processes of economic development and regeneration.Peer Reviewe

The Quantum Hamilton–Jacobi Equation and the Link Between Classical and Quantum Mechanics

We study how the classical Hamilton's principal and characteristic functions are generated from the solutions of the quantum Hamilton–Jacobi equation. While in the classically forbidden regions these quantum quantities directly tend to the classical ones, this is not the case in the allowed regions. There, the limit is reached only if the quantum fluctuations are eliminated by means of coarse-graining averages. Analogously, the classical Hamilton–Jacobi scheme bringing to the motion's equations arises from a similar formal quantum procedure.Quanta 2022; 11: 42–52

The City and the Territory System: Towards The "New Humanism" Paradigm

Abstract In this time of great transformations (increasing urbanization, climate change, biodiversity loss, growing disparities etc) we are searching a new development model, able to better satisfy the needs of all people. The "revised" traditional city model, (that is linked to a specific territory, to localism, to recognize the local identities that make the differences with their specific Heritage, based on circular/closed processes and robust relationships between city and territory; on face-to-face relationships (and not only to digital/virtual ones) attentive to the valorization of local tangible and intangible resources,exploiting differences in order to make sites more attractive to localization of talents, investments, specialized skills, that is to increase productivity), assumes the centrality of concrete relationships between the city and the territory, between inhabitants and nature. This perspective moving towards a new urban paradigm has been implemented in some small-size cities (slowcities)

Evaluation of the Feynman Propagator by Means of the Quantum Hamilton-Jacobi Equation

It is shown that the complex phase of the Feynman propagator is a solution of the quantum Hamilton–Jacobi equation, namely, it is the quantum Hamilton's principal function (or quantum action). Therefore, the Feynman propagator can be computed either by means of the path integration, or by the way of the Hamilton–Jacobi equation. This is analogous to what happens in classical mechanics, where the Hamilton's principal function can be computed either by integrating the Lagrangian along the extremal paths, or as a solution of partial differential equation, namely the classical Hamilton–Jacobi equation. If the path is decomposed in the classical one and quantum fluctuations, the contribution of these quantum fluctuations satisfies a non-linear partial differential equation, whose coefficients depend on the classical action. When the contribution of the quantum fluctuations depend only on the time, it can be computed by means of a simple integration. The final results for the propagators in this case are equal to the Van Vleck–Pauli–Morette expressions, even though the two derivations are quite different.Quanta 2023; 12: 22–26