Measurement of turbulent correlations in a coaxial flow of dissimilar fluids

Axial turbulence measurements in coaxial flow of dissimilar gase

The valuation of GMWB variable annuities under alternative fund distributions and policyholder behaviours

In this paper, we present a dynamic programming algorithm for pricing variable annuities with Guaranteed Minimum Withdrawal Benefits (GMWB) under a general Lévy processes framework. The GMWB gives the policyholder the right to make periodical withdrawals from her policy account even when the value of this account is exhausted. Typically, the total amount guaranteed for withdrawals coincides with her initial investment, providing then a protection against downside market risk. At each withdrawal date, the policyholder has to decide whether, and how much, to withdraw, or to surrender the contract. We show how different policyholder’s withdrawal behaviours can be modelled. We perform a sensitivity analysis comparing the numerical results obtained for different contractual and market parameters, policyholder behaviours and different types of Lévy processes

Geometric classical and total correlations via trace distance

We introduce the concepts of geometric classical and total correlations through Schatten 1-norm (trace norm), which is the only Schatten p-norm able to ensure a well-defined geometric measure of correlations. In particular, we derive the analytical expressions for the case of two-qubit Bell-diagonal states, discussing the superadditivity of geometric correlations. As an illustration, we compare our results with the entropic correlations, discussing both their hierarchy and monotonicity properties. Moreover, we apply the geometric correlations to investigate the ground state of spin chains in the thermodynamic limit. In contrast to the entropic quantifiers, we show that the classical correlation is the only source of 1-norm geometric correlation that is able to signaling an infinite-order quantum phase transition.Comment: v2: published versio

Estromatolitos pelágicos fosfatados relacionados con discontinuidades estratigráficas en el Cretácico del Penibético (provincia de Málaga)

En relación con discontinuidades estratigráficas en el Cretácico del Penibético se encuentran estromatolitos pelágicos fosfatados, constituidos por apatito criptocristalino (3 al 45 %). Muestran dos tipos  de morfologías: a.- Oncoides en el seno de sedimentos. b.- Recubrimientos de superficies de paleokarst con morfología nodular, LLM o laminar. Son estructuras organosedimentarias constituidas por asoci aciones simbióticas de bacterias y foraminíferos encostrantes que se formaron en un alto fondo marino, en medio reductor, a profundidades próximas al nivel de mínimo contenido en oxígeno y en una zona afectada por corrientes ascendente

Finding Connected Secluded Subgraphs

Problems related to finding induced subgraphs satisfying given properties form one of the most studied areas within graph algorithms. Such problems have given rise to breakthrough results and led to development of new techniques both within the traditional P vs NP dichotomy and within parameterized complexity. The Pi-Subgraph problem asks whether an input graph contains an induced subgraph on at least k vertices satisfying graph property Pi. For many applications, it is desirable that the found subgraph has as few connections to the rest of the graph as possible, which gives rise to the Secluded Pi-Subgraph problem. Here, input k is the size of the desired subgraph, and input t is a limit on the number of neighbors this subgraph has in the rest of the graph. This problem has been studied from a parameterized perspective, and unfortunately it turns out to be W[1]-hard for many graph properties Pi, even when parameterized by k+t. We show that the situation changes when we are looking for a connected induced subgraph satisfying Pi. In particular, we show that the Connected Secluded Pi-Subgraph problem is FPT when parameterized by just t for many important graph properties Pi

Observation of environment-induced double sudden transitions in geometric quantum correlations

Correlations in quantum systems exhibit a rich phenomenology under the effect of various sources of noise. We investigate theoretically and experimentally the dynamics of quantum correlations and their classical counterparts in two nuclear magnetic resonance setups, as measured by geometric quantifiers based on trace-norm. We consider two-qubit systems prepared in Bell diagonal states, and perform the experiments in decohering environments resulting from Bell diagonal-preserving Markovian local noise. We then report the first observation of environment-induced double sudden transitions in the geometric quantum correlations, a genuinely nonclassical effect not observable in classical correlations. The evolution of classical correlations in our physical implementation reveals in turn the finite-time relaxation to a pointer basis under nondissipative decoherence, which we characterize geometrically in full analogy with predictions based on entropic measures.Comment: 5 pages, 2 figures. v2: Minor corrections. Published versio

El financiamiento irregular de los partidos políticos: cuestiones fenomenológicas (especial referencia al caso boliviano)

[ES] Se centra en investigar de qué manera los partidos políticos obtienen su financiamiento para participar en las contiendas electorales, identificando fuentes públicas y privadas en función de las normas legales que reglamentan la actividad política y su participación en las elecciones

Estromatolitos pelágicos fosfatados relacionados con discontinuidades estratigráficas en el Cretácico del Penibético (provincia de Málaga)

En relación con discontinuidades estratigráficas en el Cretácico del Penibético se encuentran estromatolitos pelágicos fosfatados, constituidos por apatito criptocristalino (3 al 45 %). Muestran dos tipos  de morfologías: a.- Oncoides en el seno de sedimentos. b.- Recubrimientos de superficies de paleokarst con morfología nodular, LLM o laminar. Son estructuras organosedimentarias constituidas por asoci aciones simbióticas de bacterias y foraminíferos encostrantes que se formaron en un alto fondo marino, en medio reductor, a profundidades próximas al nivel de mínimo contenido en oxígeno y en una zona afectada por corrientes ascendente