Asymptotically anomalous black hole configurations in gravitating nonlinear electrodynamics

We analyze the class of non-linear electrodynamics minimally coupled to gravitation supporting asymptotically flat \textit{non Schwarzschild-like} elementary solutions. The Lagrangian densities governing the dynamics of these models in flat space are defined and fully characterized as a subclass of the set of functions of the two standard field invariants, restricted by requirements of regularity, parity invariance and positivity of the energy, which are necessary conditions for the theories to be physically admissible. Such requirements allow for a complete characterization and classification of the geometrical structures of the elementary solutions for the corresponding gravity-coupled models. In particular, an immediate consequence of the requirement of positivity of the energy is the asymptotic flatness of gravitating elementary solutions for any admissible model. The present analysis, together with the (already published) one concerning the full class of admissible gravitating non-linear electrodynamics supporting asymptotically flat \textit{Schwarzschild-like} elementary solutions, completes and exhausts the study of the gravitating point-like charge problem for this kind of models.Comment: 12 pages, 6 figures, revtex4, added extra paragraph in conclusions, added some references, added other minor changes, to published in Phys.Rev.

Non-topological solitons in field theories with kinetic self-coupling

We investigate some fundamental features of a class of non-linear relativistic lagrangian field theories with kinetic self-coupling. We focus our attention upon theories admitting static, spherically symmetric solutions in three space dimensions which are finite-energy and stable. We determine general conditions for the existence and stability of these non-topological soliton solutions. In particular, we perform a linear stability analysis that goes beyond the usual Derrick-like criteria. On the basis of these considerations we obtain a complete characterization of the soliton-supporting members of the aforementioned class of non-linear field theories. We then classify the family of soliton-supporting theories according to the central and asymptotic behaviors of the soliton field, and provide illustrative explicit examples of models belonging to each of the corresponding sub-families. In the present work we restrict most of our considerations to one and many-components scalar models. We show that in these cases the finite-energy static spherically symmetric solutions are stable against charge-preserving perturbations, provided that the vacuum energy of the model vanishes and the energy density is positive definite. We also discuss briefly the extension of the present approach to models involving other types of fields, but a detailed study of this more general scenario will be addressed in a separate publication.Comment: 5 pages, 1 figure, revtex4, minor corrections adde

Phenomenological research on professsional knowledge and educational relationship building

Following Dewey’s (1997) and Schwab’s (2013) ideas, Clandinin & Connelly (1992) developed their notion of teacher as curriculum maker, it means, the “teacher not so much as a maker of curriculum but as a part of it and to imagine a place for contexts, culture (Dewey´s notion of interaction), and temporality (both past and future contained in Dewey´s notion of continuity)” (p.365). In this way, teachers are not seen as implementers of curricular plans but as part of the curriculum making process. In other words, they understand that students create their curriculum in their experience at school when they interact with teachers and the environment. Therefore, the educational relationship creates the framework where learning can take place and students can build knowledge (Atkinson, 2015); it means, relationships generate meeting places that allow the making and reshaping of curriculum. If teaching takes place in the relationship, it means recognition (and acceptance) of the other person, of the otherness. It supposes trying to come into relation with the other, and it implies also acceptance of the uncertainty that otherness has. Therefore, education Is not about the implementation of an education programme in order to achieve (pre)determined results. It is not about intervention on students, but it is an experience of relationship where each one constructs their own story (Molina, Blanco & Arbiol, 2016). In short, curriculum is made through experiences that are lived in relation and, therefore, we could say that education is an act of relationship (Piussi, 2006). In this way, education does not require that teachers have the most appropriate knowledge and programme for every situation; the educational experience is unpredictable and ineffable, we cannot anticipate or face it completely (Van Manen, 2015). Thus, teaching requires becoming aware of how we build relationships and how we see the other person (Contreras, 2002).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Strategic Procurement, Openness and Market Structure

We examine strategic procurement behaviour by governments and its effect on market structure in sectors, such as defence, where the government is the dominant consumer. In a world economy with trade between producers, and between producers and non-producers, we use a modified Dixit-Stiglitz utility function with an indepen- dent taste for variety. Governments can, in effect, choose the number of domestic firms and their size by adjusting the procurement price. Unlike the standard model with no independent taste for variety and no external sector of non-producers, there are incentives for subsidies, openness impacts on industrial structure and there are potential gains from procurement coordination between producer countries.procurement, openness, market structure, defence and pharmaceutical sectors

Parallel imports, innovations and national welfare: The role of the sizes of the income classes and national markets for health care.

This paper shows that regardless of any intra-country income differences, parallel imports result in a lower level of health-care innovation but, contrary to popular as well as conventional theoretical wisdom, a lower price in the Third World compared to market-based discrimination. Despite such a lower price, however, parallel imports unambiguously make all buyers in the Third World worse off when intra-country income disparity exists. On the other hand, even discarding the MNC's profit, there will be cases in which the richer country prefers price discrimination as well. That is, in those cases, no countries will have any incentive under the welfare criterion to undo price discrimination, contrary to Richardso