Progress in the dynamical parton distributions

The present status of the (JR) dynamical parton distribution functions is reported. Different theoretical improvements, including the determination of the strange sea input distribution, the treatment of correlated errors and the inclusion of alternative data sets, are discussed. Highlights in the ongoing developments as well as (very) preliminary results in the determination of the strong coupling constant are presented.Comment: 4 pages, 1 figure, Talk given at the XX International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS2012

GENERALIZED VECTOR RISK FUNCTIONS

The paper introduces a new notion of vector-valued risk function. Both deviations and expectation bounded coherent risk measures are defined and analyzed. The relationships with both scalar and vector risk functions of previous literature are discussed, and it is pointed out that this new approach seems to appropriately integrate several preceding point of view. The framework of the study is the general setting of Banach lattices and Bochner integrable vector-valued random variables. Sub-gradient linked representation theorems, as well as portfolio choice problems, are also addressed, and general optimization methods are presented. Finally, practical examples are provided.

Phantom inflation and the "Big Trip"

Primordial inflation is regarded to be driven by a phantom field which is here implemented as a scalar field satisfying an equation of state $p=\omega\rho$, with $\omega<-1$. Being even aggravated by the weird properties of phantom energy, this will pose a serious problem with the exit from the inflationary phase. We argue however in favor of the speculation that a smooth exit from the phantom inflationary phase can still be tentatively recovered by considering a multiverse scenario where the primordial phantom universe would travel in time toward a future universe filled with usual radiation, before reaching the big rip. We call this transition the "big trip" and assume it to take place with the help of some form of anthropic principle which chooses our current universe as being the final destination of the time transition.Comment: 23 pages, 5 figures, LaTex, Phys. Lett. B (in press

Summary of the Structure Functions Working group at DIS 2012

A summary of the recent experimental, phenomenological and theoretical results presented in the Structure Functions working group at DIS2012 workshop.Comment: 12 pages, 9 figures, to be published in the Proceedings of the XX International Workshop on Deep Inelastic Scattering, University of Bonn, 26-30th March 201

Four temptations against urban renewel: an approach to fur current urban processes

Comunicación presentada en 25 European Network housing Research International Conference. Tarragona 19 al 22 junio 2013The new paradigm of urban social and economic rehabilitation is replacing the current sprawl growth model. But four temptations must be considered: 1) The high-density. This process is possible in sprawl model, but its quantification does not seem to be clear, because after a certain threshold of occupancy per unit area, the city seems to collapse and social and environmental benefits disappear, appearing reversal processes city to country in search of a minimum quality of life standards. There is not a model for appropriate density. It depends on the way of life of population, the traditional city model. 2) The replacement. Architectonic and urban rehabilitation must be preferred to replacement, except for certain cases to be legally taxed. But as the city cannot be densified and orderly, without the prior replacement of the building, may fit this temptation. Even replacing the building can be made without considering high building standards 3) The gentrification. There is a wide doctrine and experience about this phenomenon with serious social consequences. It is very tempting to replace the building, due to improve requirement of broad levels of quality, entering a game of speculation, so common in our real estate market. 4) The eco-city. Comprehensive projects are building spaces with low levels of energy consumption. Fall into this temptation means to continue the extensive city model we have been developing, creating new cities far from the existing but incorporating saving measures, and continuing resource consumptio

Sustentabilidad urbana planteamientos teóricos y conceptuales

El estudio del fenómeno ambiental en nuestras ciudades es fundamental para alcanzar una mejor calidad de vida de nuestra sociedad; el desarrollo sostenible busca aminorar los estragos de la urbanización acelerada y del modo de producción predominante. A pesar de que han surgido alternativas teóricas y conceptuales para caracterizar el fenómeno, como es el desarrollo sustentable, Ecodesarrollo, la Globalización y el Comercio Internacional y desarrollo urbano sustentable, éstas se consideran insuficientes y/o han tenido deficiencias en su operación, además de que no han dado los resultados esperados al entendimiento del objeto de estudio.El estudio del fenómeno ambiental en nuestras ciudades es fundamental para alcanzar una mejor calidad de vida de nuestra sociedad; el desarrollo sostenible busca aminorar los estragos de la urbanización acelerada y del modo de producción predominante. A pesar de que han surgido alternativas teóricas y conceptuales para caracterizar el fenómeno, como es el desarrollo sustentable, Ecodesarrollo, la Globalización y el Comercio Internacional y desarrollo urbano sustentable, éstas se consideran insuficientes y/o han tenido deficiencias en su operación, además de que no han dado los resultados esperados al entendimiento del objeto de estudio

Martingales and Arbitrage: a new look

This paper addresses the equivalence between the absence of arbitrage and the existence of equivalent martingale measures. The equivalence will be established under quite weak assumptions since there are no conditions on the set of trading dates (it may be finite or countable, with bounded or unbounded horizon, etc.) or on the trajectories of the price process (for instance, they do not have to be right-continuous). Besides we will deal with arbitrage portfolios rather than free-lunches. The concept of arbitrage is much more intuitive than the concept of free lunch and has more clear economic interpretation. Furthermore it is more easily tested in theoretical models or practical applications. In order to overcome the usual mathematical difficulties arising when dealing with arbitrage strategies, the set of states of nature will be widened by drawing on projective systems of Radon probability measures, whose projective limit will be the martingale measure. The existence of densities between the "real" probabilities and the "risk-neutral" probabilities will be guaranteed by introducing the concept of "projective equivalence". Hence some classical counter-examples will be solved and a complete characterization of the absence of arbitrage will be provided in a very general framework.Research partially supported by “Comunidad Autónoma de Madrid” (Spain), Grant s-0505/tic/000230, and “MEyC” (Spain), Grant SEJ2006-15401-C04Publicad