Tachyonic Quintessential Inflation

We study the possibility to construct an observationally viable scenario where both early Inflation and the recently detected accelerated expansion of the universe can be explained by using a single scalar field associated with the Tachyon. The Reheating phase becomes crucial to enable us to have a consistent cosmology and also to get a second accelerated expansion period. A discussion using an exponential potential is presented.Comment: 5 pages, Revtex4. Added some references. To be published in Physical Review

Dark energy and Dark matter interaction in light of the second law of thermodynamics

In the context of thermodynamics we discuss the way inevitable emerge an interaction between dark components, and in this way, provide a mechanism to understand the limits of the LCDM model and the class of interaction models between dark components. Using observational data we have tested two models of explicit interaction between dark components and reconstructed the evolution of temperatures for both components. We found that observations suggest the interaction exist with energy flowing from dark energy to dark matter. The best fit also suggest a phantom equation of state parameter for dark energy. We discuss the results having in mind the constraints imposed by thermodynamics.Comment: 18 pages, 4 figure

DFIT: An R Package for Raju's Differential Functioning of Items and Tests Framework

This paper presents DFIT, an R package that implements the differential functioning of items and tests framework as well as the Monte Carlo item parameter replication approach for producing cut-off points for differential item functioning indices. Furthermore, it illustrates how to use the package to calculate power for the NCDIF index, both post hoc, as has regularly been the case in differential item functioning empirical and simulation studies, as well as a priori given certain item parameters. The version reviewed here implements all DFIT indices and Raju's area measures for tests comprised of items modeled with the same parametric item response unidimensional model (1-, 2-, and 3-parameters, generalized partial credit model or graded response model), the Mantel-Haenszel statistic with an underlying dichotomous item response model, and the item parameter replication method for any of the estimated indices with dichotomous item response models

Cantilever dynamics in amplitude modulation AFM: continuous and discontinuous transitions

Transitions between the attractive and the repulsive force regimes for amplitude modulation atomic force microscopy (AFM) can be either discontinuous, with a corresponding jump in amplitude and phase, or continuous and smooth. During the transitions, peak repulsive and average forces can be up to an order of magnitude higher when these are discrete. Under certain circumstances, for example, when the tip radius is relatively large (e.g. R > 20–30 nm) and for high cantilever free amplitudes (e.g. A0 > 40–50 nm), the L state can be reached with relatively low set-points only (e.g. Asp/A0 < 0.30). We find that these cases do not generally lead to higher resolution but increase the background noise instead. This is despite the fact that the imaging can be non-contact under these conditions. The appearance of background noise is linked to increasing cantilever mean deflection and tip–surface proximity with increasing free amplitude in the L state. Cantilever dynamics in amplitude modulation AFM: Continuous and discontinuous transitions (PDF Download Available). Available from: https://www.researchgate.net/publication/231025693_Cantilever_dynamics_in_amplitude_modulation_AFM_Continuous_and_discontinuous_transitions [accessed Mar 27, 2017].Peer ReviewedPostprint (author's final draft

Towards a Democratization of Knowledge with Topological Emphasis in Economics

Abstract. We formulate and prove a theorem which consists in how the natural endogenous antagonist interaction of agents who look for understanding a generalizable phenomenon, results in a tendency towards chaos. This takes us to the final absolution of implementing the majority rule as the only instrument that generates socially acceptable knowledge, escaping from the chaos tendency. Finally, we extend our analysis to consider the arise of multiple simultaneous antagonist postures on the explanation of a phenomenon, and through an application of the Pythagoras theorem, we prove that it takes less effort or sacrifice for an agent to learn strategically to get an explanation, than if she was the creator of the concerning knowledge, which implies different consequences of possible topological private and public tendencies.Keywords. Antagonist endogenous knowledge, Social entropy, Chaos theorem, Social choice.JEL. B50, O31, O35

El Amor al Mundo en tiempos de oscuridad. Un siglo de Hannah Arendt, una pensadora secular

Se cumple un siglo del nacimiento de Hannah Arendt. Según Heidegger, el indicio más seguro de la creatividad de un pensamiento es la discusión que provoca. A más de treinta años de su muerte, siguen apareciendo traducciones castellanas así como tesis y críticas sobre su legado.Sin embargo, la predominancia de lo político en élno oculta su conexión con otras dimensiones(narratividad, memoria, juicio, etc.) ni tampoco, sobre todo, su fundamento en un interés originario y mayor por el humano como un ser espacial, un ser de vínculos. Como alguien que necesita delmundo y es necesitado, individualmente, por el mundo. El amor mundi es la gran inspiración de su obra intelectual. Una respuesta generosa a la experiencia de haber presenciado y sido víctima dela destrucción del mundo

Loneliness, Writing and Celebration of the Finite Condition into The Essays of Michel de Montaigne

Montaigne traza una conciencia de la individualidad en un punto medio que evita tanto la deploración del yo del luteranismo como la absolutización de la razón del cartesianismo. Somos un punto en el tiempo y el espacio, pequeñez que desestima cualquier divinización del juicio personal y, de paso, explica la pluralidad del mundo. Pequeñez que alienta tanto el trato con la interioridad como el interés por los otros.Montaigne fosters a sort of awareness of the individuality, which is halfway in between the lutheran denial of the self and the cartesian absolutization of reason. We are just a tiny dot in time and space; a fact that prevents us from deifying our person