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

A fractal LTB model cannot explain Dark Energy

We revisited the problem of describing, on average, a fractal distribution of matter using a Lemaitre-Tolman-Bondi (LTB) solution. Here we study the fractal structure of our local universe having a fractal dimension and a scale transition. We test our model with the latest type Ia supernova data, the Pantheon compilation, and discuss problems and possible improvements for it, concluding that a fractal transition in LTB cosmology cannot be used to explain the effects of dark energy but it can be useful to study structures at low scales

R^2-corrections to Chaotic Inflation

Scalar density cosmological perturbations, spectral indices and reheating in a chaotic inflationary universe model, in which a higher derivative term is added, are investigated. This term is supposed to play an important role in the early evolution of the Universe, specifically at times closer to the Planck era.Comment: 14 pages, accepted for publication in MPL

Improve the production and quality of milk malagueña goat by the identification and validation of genetic markers (QTLs)

Motivation:Malagueña goat is one of the most dairy goat breeds in the world with an average production of 500 liters of milk, per female, per year; with approximately 300,000 animals.Currently, the Malagueña goat breed improvement program, is based on the selection of the best individuals based on morphologic criteria. So that, a greater number of morphological skills exist in a specimen, better genetic evaluation is assigned.On the other hand, for years it has been studying the association of molecular genetic markers with cheese production. Specifically, they have been described in several global locations even 18 alleles of the caseins directly related to the total protein content. There are described alleles of high, medium, low and zero protein production.In this paper we perform a genetic identification by genotyping of these alleles to validate the program to improve the Malaga goat breed.Methods:The DNA is obtained by extraction from blood and/or hair for later identification of each copy of haplotype.To this end, we perform 4 levels of diagnostic PCRs that allows us to separate high production alleles from others.Comparing the allelic frequencies obtained in a selected group as producers, with a low production control group we can validate the polymorphism of α-S1-casein protein as a marker of individual milk production.Results:Assuming that the in process method will be validated, the results will be applied to design a controlled crosses program aimed to improve the cheese degree apply

Matter production effects and interacting scenario within a reconstructed mimetic cosmology for late times

In this work we explore two possible scenarios that can be considered to extend a recent proposed model by the authors known as reconstructed mimetic cosmology. This study is complemented with an statistical analysis for each case. The first scenario considers the inclusion of matter production as a possible source of cosmic expansion in the reconstructed mimetic model, at effective level was found that this construction can cross the phantom divide, the model evolves from quintessence to phantom dark energy. The second scenario corresponds to a construction of an interacting scheme for the dark sector which is described by the unified mimetic model. The resulting interaction term (not imposed by an Ansatz), $Q$, exhibits changes of sign leading to the violation of the second law along the cosmic evolution and non adiabaticity; the temperatures for the components of the dark sector are computed and such components are shown to be out of thermal equilibrium.Comment: 24 pages, 8 figures, references added. Accepted for publication in EPJ