Condiciones para una ética económica

Estas son las cuatro cuestiones que articulan la ponencia: a) Solo puede hablarse con propiedad de “ética económica” si en un discurso estrictamente científico-económico se encuentran incorporados elementos de naturaleza ética que, en cuanto tales, jueguen a la vez en ese discurso un papel estrictamente científico-económico. b) Ese es el caso, en una economía de mercado, del concepto “demanda”. Es en el juego entre la demanda y la oferta en donde se forman los precios del mercado. La demanda constituye así un elemento “científico-técnico” en la explicación del funcionamiento “técnico” del mercado. Pero a la vez, y sin confusión con la demanda en cuanto elemento técnico del mecanismo del mercado, la demanda es portadora de sustancia ética y es susceptible por tanto de ser juzgada según criterios éticos como “buena” o como “mala” a la vez que es contemplada como elemento “técnico” determinante del precio de la droga. c) Este concepto de “ética económica” es susceptible de ser articulado dentro de una “teoría de la sociedad”. d) Un claro ejemplo de esa articulación se encuentra en la obra del economista y sociólogo alemán de la Escuela de Tubinga Albert Schäffle (1831-1903) sobre la base de la teoría de la sociedad del filósofo Karl Christian Friedrich Krause (1781-1832) que tanto influyó en España. Palabras clave: ética, economía, sociología.</p

Transport interchanges effects on their surroundings in Tunja (Colombia) and cordoba (Spain): A comparative approach

ABSTRACT: This article proposes a methodology to study the urban implications of transport interchanges. The methodology was evaluated through the study of commercial establishments and urban quality in the surroundings of two transport interchanges. The case studies are a bus station in Colombia and a combined high-speed rail and bus station in Spain. The article draws two types of conclusions; firstly, that the comparative methodology proposed is effective in determining the influence of transport interchanges and secondly that it provides specific conclusions about the activities in the station's surrounding area. The article demonstrates that the surroundings of the transport interchanges have greater commercial activity than similar areas of the city. It also concludes that the different income levels of HSR and bus users provoke a variety and quantity of commercial activities within each type of station. Furthermore, it concludes that the perceived quality of the interchange surroundings is deeply influenced by its level of integration within the urban plan, despite the negative side effects related to transport

Newtonian Collapse of Scalar Field Dark Matter

In this letter, we develop a Newtonian approach to the collapse of galaxy fluctuations of scalar field dark matter under initial conditions inferred from simple assumptions. The full relativistic system, the so called Einstein-Klein-Gordon, is reduced to the Schr\"odinger-Newton one in the weak field limit. The scaling symmetries of the SN equations are exploited to track the non-linear collapse of single scalar matter fluctuations. The results can be applied to both real and complex scalar fields.Comment: 4 pages RevTex4 file, 4 eps figure

Evolution of the Schr\"odinger--Newton system for a self--gravitating scalar field

Using numerical techniques, we study the collapse of a scalar field configuration in the Newtonian limit of the spherically symmetric Einstein--Klein--Gordon (EKG) system, which results in the so called Schr\"odinger--Newton (SN) set of equations. We present the numerical code developed to evolve the SN system and topics related, like equilibrium configurations and boundary conditions. Also, we analyze the evolution of different initial configurations and the physical quantities associated to them. In particular, we readdress the issue of the gravitational cooling mechanism for Newtonian systems and find that all systems settle down onto a 0--node equilibrium configuration.Comment: RevTex file, 19 pages, 26 eps figures. Minor changes, matches version to appear in PR

Evolution of 3D Boson Stars with Waveform Extraction

Numerical results from a study of boson stars under nonspherical perturbations using a fully general relativistic 3D code are presented together with the analysis of emitted gravitational radiation. We have constructed a simulation code suitable for the study of scalar fields in space-times of general symmetry by bringing together components for addressing the initial value problem, the full evolution system and the detection and analysis of gravitational waves. Within a series of numerical simulations, we explicitly extract the Zerilli and Newman-Penrose scalar $\Psi_4$ gravitational waveforms when the stars are subjected to different types of perturbations. Boson star systems have rapidly decaying nonradial quasinormal modes and thus the complete gravitational waveform could be extracted for all configurations studied. The gravitational waves emitted from stable, critical, and unstable boson star configurations are analyzed and the numerically observed quasinormal mode frequencies are compared with known linear perturbation results. The superposition of the high frequency nonspherical modes on the lower frequency spherical modes was observed in the metric oscillations when perturbations with radial and nonradial components were applied. The collapse of unstable boson stars to black holes was simulated. The apparent horizons were observed to be slightly nonspherical when initially detected and became spherical as the system evolved. The application of nonradial perturbations proportional to spherical harmonics is observed not to affect the collapse time. An unstable star subjected to a large perturbation was observed to migrate to a stable configuration.Comment: 26 pages, 12 figure

Bose-Einstein condensate dark matter phase transition from finite temperature symmetry breaking of Klein-Gordon fields

In this paper the thermal evolution of scalar field dark matter particles at finite cosmological temperatures is studied. Starting with a real scalar field in a thermal bath and using the one loop quantum corrections potential, we rewrite Klein-Gordon's (KG) equation in its hydrodynamical representation and study the phase transition of this scalar field due to a Z_2 symmetry breaking of its potential. A very general version of a nonlinear Schr\"odinger equation is obtained. When introducing Madelung's representation, the continuity and momentum equations for a non-ideal SFDM fluid are formulated, and the cosmological scenario with the SFDM described in analogy to an imperfect fluid is then considered where dissipative contributions are obtained in a natural way.Additional terms appear compared to those obtained in the classical version commonly used to describe the \LambdaCDM model, i.e., the ideal fluid. The equations and parameters that characterize the physical properties of the system such as its energy, momentum and viscous flow are related to the temperature of the system, scale factor, Hubble's expansion parameter and the matter energy density. Finally, some details on how galaxy halos and smaller structures might be able to form by condensation of this SF are given.Comment: Substantial changes have been made to the paper, following the referees recommendations. 16 pages. Published in Classical and Quantum Gravit

On the Space Time of a Galaxy

We present an exact solution of the averaged Einstein's field equations in the presence of two real scalar fields and a component of dust with spherical symmetry. We suggest that the space-time found provides the characteristics required by a galactic model that could explain the supermassive central object and the dark matter halo at once, since one of the fields constitutes a central oscillaton surrounded by the dust and the other scalar field distributes far from the coordinate center and can be interpreted as a halo. We show the behavior of the rotation curves all along the background. Thus, the solution could be a first approximation of a ``long exposition photograph'' of a galaxy.Comment: 8 pages REVTeX, 11 eps figure

Design and evaluation of PM Ti surfaces modified by colloidal techniques and diffusion processes for biomedical applications

The aim of this work was the modification of the composition and surface microstructure of powder metallurgy titanium to improve the wear resistance and reduce the elastic modulus while maintaining the corrosion behavior, characteristics needed for biomedical applications. For this purpose, Mo and Nb coatings were produced by colloidal techniques. Stable aqueous suspensions were prepared from micro-sized powder of Mo and Nb particles, deposited onto the powder metallurgy titanium substrates (green or sintered). After a heat treatment to promote the diffusion and the consolidation of the layers, microstructural changes were obtained. In the case of green substrates, the co-sintering process provides a diffusion depth of 85-100 micron. In the as-sintered case, a uniform depth of 40-65 microns was reached. The surfaces were characterised by micro-hardness, corrosion and tribocorrosion testing, and the results showed that hardened surfaces presented lower tendency to corrosion both under static conditions and under sliding.Funds were provided by Spanish Government (programme MINECO, ref. MAT2012-38650-C02-01), Regional Government of Madrid (programme MULTIMAT-CHALLENGE, ref. S2013/MIT-2862) and Institute of Alvaro Alonso Barba (IAAB) for the research stay in CMEMS-UMINHO (University of Minho).info:eu-repo/semantics/publishedVersio