Financial information and restructuring of spanish savings banks in a context of crisis. Changes in the regulation; content and evolution of FROB

The worsening of the financial crisis in September 2008, coinciding with the collapse of Lehman Brothers, set off unprecedented action in the European states to support the stability of their markets and financial institutions. Different forums asked for joint and faster implementation. This lead the Spanish authorities to take a series of measures. In the first part of this paper we make a theoretical review of previous studies at international level on early warning systems and about prediction of failure in the banking sector. No doubt it helps to situate and understand better the later Spanish analysis, why it is necessary and its development. We also analyze the evolution of the Spanish financial system between 2008-2011 with the focus on explaining the reform and restructuring of savings banks. Specifically, a study of the accounting and financial standards evolution is made, as well as an examination of the changes in banking regulations that emerged during this period and the role of the Banking Management Restructuring Fund (FROB) and the Institutional Protection Systems (SIP).FROB, SIP, banking regulation changes, early warning systems.

Dark matter and halo bispectrum in redshift space: theory and applications

We present a phenomenological modification of the standard perturbation theory prediction for the bispectrum in redshift space that allows us to extend the model to mildly non-linear scales over a wide range of redshifts, $z\leq1.5$. We find that we can describe the bispectrum of dark matter particles with $\sim5$ accuracy for $k_i\lesssim0.10\,h/{\rm Mpc}$ at $z=0$, for $k_i\lesssim0.15\,h/{\rm Mpc}$ at $z=0.5$, for $k_i\lesssim0.17\,h/{\rm Mpc}$ at $z=1.0$ and for $k_i\lesssim0.20\,h/{\rm Mpc}$ at $z=1.5$. We also test that the fitting formula is able to describe with similar accuracy the bispectrum of cosmologies with different $\Omega_m$, in the range $0.2\lesssim \Omega_m \lesssim 0.4$, and consequently with different values of the logarithmic grow rate $f$ at $z=0$, $0.4\lesssim f(z=0) \lesssim 0.6$. We apply this new formula to recover the bias parameters, $f$ and $\sigma_8$, by combining the redshift space power spectrum monopole and quadrupole with the bispectrum monopole for both dark matter particles and haloes. We find that the combination of these three statistics can break the degeneracy between $b_1$, $f$ and $\sigma_8$. For dark matter particles the new model can be used to recover $f$ and $\sigma_8$ with $\sim1$ accuracy. For dark matter haloes we find that $f$ and $\sigma_8$ present larger systematic shifts, $\sim10$. The systematic offsets arise because of limitations in the modelling of the interplay between bias and redshift space distortions, and represent a limitation as the statistical errors of forthcoming surveys reach this level. Conveniently, we find that these residual systematics are mitigated for combinations of parameters. The improvement on the modelling of the bispectrum presented in this paper will be useful for extracting information from current and future galaxy surveys. [abridged]Comment: 37 pages, 17 figures, 8 tables. Published in JCA

Reducing sample variance: halo biasing, non-linearity and stochasticity

Comparing clustering of differently biased tracers of the dark matter distribution offers the opportunity to reduce the cosmic variance error in the measurement of certain cosmological parameters. We develop a formalism that includes bias non-linearities and stochasticity. Our formalism is general enough that can be used to optimise survey design and tracers selection and optimally split (or combine) tracers to minimise the error on the cosmologically interesting quantities. Our approach generalises the one presented by McDonald & Seljak (2009) of circumventing sample variance in the measurement of $f\equiv d \ln D/d\ln a$. We analyse how the bias, the noise, the non-linearity and stochasticity affect the measurements of $Df$ and explore in which signal-to-noise regime it is significantly advantageous to split a galaxy sample in two differently-biased tracers. We use N-body simulations to find realistic values for the parameters describing the bias properties of dark matter haloes of different masses and their number density. We find that, even if dark matter haloes could be used as tracers and selected in an idealised way, for realistic haloes, the sample variance limit can be reduced only by up to a factor $\sigma_{2tr}/\sigma_{1tr}\simeq 0.6$. This would still correspond to the gain from a three times larger survey volume if the two tracers were not to be split. Before any practical application one should bear in mind that these findings apply to dark matter haloes as tracers, while realistic surveys would select galaxies: the galaxy-host halo relation is likely to introduce extra stochasticity, which may reduce the gain further.Comment: 21 pages, 13 figures. Published version in MNRA

Optimal Redshift Weighting For Redshift Space Distortions

The low statistical errors on cosmological parameters promised by future galaxy surveys will only be realised with the development of new, fast, analysis methods that reduce potential systematic problems to low levels. We present an efficient method for measuring the evolution of the growth of structure using Redshift Space Distortions (RSD), that removes the need to make measurements in redshift shells. We provide sets of galaxy-weights that cover a wide range in redshift, but are optimised to provide differential information about cosmological evolution. These are derived to optimally measure the coefficients of a parameterisation of the redshift-dependent matter density, which provides a framework to measure deviations from the concordance $\Lambda$CDM cosmology, allowing for deviations in both geometric and/or growth. We test the robustness of the weights by comparing with alternative schemes and investigate the impact of galaxy bias. We extend the results to measure the combined anisotropic Baryon Acoustic Oscillation (BAO) and RSD signals.Comment: 10 pages, 5 figures, submitted to MNRA

Processing Collections of Geo-Referenced Images for Natural Disasters

After disaster strikes, emergency response teams need to work fast. In this context, crowdsourcing has emerged as a powerful mechanism where volunteers can help to process different tasks such as processing complex images using labeling and classification techniques. In this work we propose to address the problem of how to efficiently process large volumes of georeferenced images using crowdsourcing in the context of high risk such as natural disasters. Research on citizen science and crowdsourcing indicates that volunteers should be able to contribute in a useful way with a limited time to a project, supported by the results of usability studies. We present the design of a platform for real-time processing of georeferenced images. In particular, we focus on the interaction between the crowdsourcing and the volunteers connected to a P2P network.Facultad de Informátic

Modified w-distances on quasi-metric spaces and a fixed point theorem on complete quasi-metric spaces

This is the author’s version of a work that was accepted for publication in Topology and its Applications. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Topology and its Applications, [Volume 203, 15 April 2016, Pages 32-41] https://doi.org/10.1016/j.topol.2015.12.073¨[EN] In this paper we introduce the notion of modified w-distance (mw-distance) on a quasi-metric space which generalizes the concept of quasi-metric. We obtain a fixed point theorem for generalized contractions with respect to mw-distances on complete quasi-metric spaces.The authors acknowledge the support of the Ministry of Economy and Competitiveness of Spain, Grant MTM2012-37894-C02-01.Alegre Gil, MC.; Marín Molina, J. (2016). Modified w-distances on quasi-metric spaces and a fixed point theorem on complete quasi-metric spaces. Topology and its Applications. 203:32-41. https://doi.org/10.1016/j.topol.2015.12.073S324120