Diversity as a project strategy in urban transformation

El proceso de deslocalización de la segunda mitad del siglo xx y la reflexión acerca de la utilización de nuevos mecanismos de planeamiento, proyecto y gestión urbana en la ciudad consolidada crearon la oportunidad de intervenciones de larga escala en las periferias industriales históricas. El proyecto de transformación urbana responde a las especificidades de este territorio entrecortado por obstáculos de diferente naturaleza y contaminado por variadas preexistencias de su pasado industrial, creando nuevas actividades y nuevas oportunidades para barrios periféricos. Basado en la tesis de doctorado desarrollada sobre diferentes intervenciones urbanas, el presente artículo estudia las estrategias de diversidad utilizadas en los proyectos de transformación urbana en la definición de los trazados y en la composición de los volúmenes edificados para evaluar el encaje del nuevo fragmento urbano en su contexto.The process of industry relocation of the second half of the twentieth century and the reflection on the use of new mechanisms for planning, design and urban management in the consolidated city, created an opportunity to large scale interventions in the historical industrial peripheries. The urban transformation project responds to the specificity of this territory, interrupted by obstacles of different kinds and pre-existing conditions by its industrial past, and creating new activities gives new opportunities for suburbs. The present article examines the different strategies used, defining paths and the composition of the built volumes in urban transformation projects to evaluate the fit the new urban fragment in their contextPeer Reviewe

Unitary expansion of the time evolution operator

We propose an expansion of the unitary evolution operator, associated to a given Schr\"odinger equation, in terms of a finite product of explicit unitary operators. In this manner, this unitary expansion can be truncated at the desired level of approximation, as shown in the given examples.Comment: 6 pages, 7 figures. Updated version, minor final change

Tunneling catastrophes of the partition function

We use path-integrals to derive a general expression for the semiclassical approximation to the partition function of a one-dimensional quantum-mechanical system. Our expression depends solely on ordinary integrals which involve the potential. For high temperatures, the semiclassical expression is dominated by single closed paths. As we lower the temperature, new closed paths may appear, including tunneling paths. The transition from single to multiple-path regime corresponds to well-defined catastrophes. Tunneling sets in whenever they occur. Our formula fully accounts for this feature

Scaling of variables and the relation between noncommutative parameters in Noncommutative Quantum Mechanics

We consider Noncommutative Quantum Mechanics with phase space noncommutativity. In particular, we show that a scaling of variables leaves the noncommutative algebra invariant, so that only the self-consistent effective parameters of the model are physically relevant. We also discuss the recently proposed relation of direct proportionality between the noncommutative parameters, showing that it has a limited applicability.Comment: Revtex4, 4 pages; version to match the published on