Equation of state and singularities in FLRW cosmological models

We consider FLRW cosmological models with standard Friedmann equations, but leaving free the equation of state. We assume that the dark energy content of the universe is encoded in an equation of state p = f(ρ), which is expressed with most generality in the form of a power expansion. The inclusion of this expansion in Friedmann equations allows us to construct a perturbative solution and to relate the coefficients of the equation of state with the formation of singularities of different types

Cosmological singularities and modified theories of gravity

We consider perturbative modifications of the Friedmann equations in terms of density corresponding to modified theories of gravity proposed as an alternative route to comply with the observed accelerated expansion of the universe. Assuming that the present matter content of the universe is a pressureless fluid, the possible singularities that may arise as the final state of the universe are surveyed. It is shown that, at most, two coefficients of the perturbative expansion of the Friedman equations are relevant for the analysis. Some examples of application of the perturbative scheme are included

Phenomenology of Unified Dark Matter models with fast transition

A fast transition between a standard matter-like era and a late $\Lambda$CDM-like epoch generated by a single Unified Dark Matter component can explain the observed acceleration of the Universe. UDM models with a fast transition should be clearly distinguishable from $\Lambda$CDM (and alternatives) through observations. Here we focus on a particularly simple model and analyse its viability by studying features of the background model and properties of the adiabatic UDM perturbations.Comment: 4 pages, 1 figure, Proceedings of the Spanish Relativity Meeting ERE2012, University of Minho, Guimar\~aes, Portugal, September 3-7, 201

Classification of cosmological milestones

In this paper causal geodesic completeness of FLRW cosmological models is analysed in terms of generalised power expansions of the scale factor in coordinate time. The strength of the found singularities is discussed following the usual definitions due to Tipler and Krolak. It is shown that while classical cosmological models are both timelike and lightlike geodesically incomplete, certain observationally alllowed models which have been proposed recently are lightlike geodesically complete.Comment: RevTeX 4, 12 page

Uncertainty, reconstruction and resistance: young adults' responses to religious diversity in Spain and the UK.

Young people in diverse societies routinely encounter worldviews different from their own, but we know relatively little about how these encounters affect them. This study investigated how young adults in Britain and Spain respond to encounters with other worldviews, focusing on whether and how their existing worldviews were affected. We conducted semi-structured interviews with twenty participants. Thematic and narrative analyses revealed three main responses: uncertainty, reconstruction and resistance. Encounters with alternative worldviews often led young people to feel uncertain about their own beliefs, particularly those which they understood to be contradicted by the alternative worldview. Reconstruction occurred when participants adopted elements of newly encountered worldviews to create an idiosyncratic religiosity or spirituality. Resistance captured those instances where participants dismissed alternative worldviews as epistemologically or morally problematic. The findings indicate that young people in the UK and Spain are responding in several distinct ways to religious diversity

The use of religious metaphors by UK newspapers to describe and denigrate climate change.

British newspapers have denigrated anthropogenic climate change by misrepresenting scientific consensus and/or framing climate change within unsympathetic discourses. One aspect of the latter that has not been studied is the use of metaphor to disparage climate change science and proponents.This article analyses 122 British newspaper articles published using a religious metaphor between summer 2003 and 2008. Most were critical of climate change, especially articles in conservative newspapers The Daily Telegraph, Daily Mail and The Times. Articles used religion as a source of metaphor to denigrate climate change in two ways: (1) undermining its scientific status by presenting it as irrational faith-based religion, and proponents as religious extremists intolerant of criticism; (2) mocking climate change using notions of sin, e.g. describing ‘green’ behaviours as atonement or sacrifice.We argue that the religious metaphor damages constructive debate by emphasizing morality and how climate change is discussed, and detracting attention from the content of scientific data and theories

Epistolario de Vicente Aleixandre a José Ángel Valente

Presentamos en esta tesis un corpus de cartas cuya trascripción y anotación constituye la parte central de la investigación realizada. El material que se pone a disposición de los filólogos se encuentra archivado en la Cátedra José Ángel Valente de Poesía e Estética, dependiente de la Universidad de Santiago de Compostela. Después de centrarnos en la organización del material relativo a la correspondencia mantenida por carta entre los poetas Vicente Aleixandre y José Ángel Valente ofrecemos la edición del epistolario, que muestra cómo vida y obra se interrelacionan de tal manera que es imposible separar en las cartas estos dos aspectos, tan íntimamente relacionados para el poeta del 27

Entrevista a Xosé Luís Axeitos, secretario da Real Academia Galega

Xosé Luís Axeitos Agrelo foi catedrático de Lingua e Literatura Españolas no Instituto Rafael Dieste e profesor da U.N.E.D. na Coruña. Dende o 23 de xaneiro de 2010 é Secretario da Real Academia Galega, institución na que ingresou o 30 de outubro de 2004, desempeñando os cargos de arquiveiro e bibliotecario. Mais a súa principal contribución á cultura galega é sen dúbida o seu gran labor como estudoso, erudito, editor e documentalista da literatura contemporánea. Nesta entrevista interesámonos pola súa faceta como editor de textos e crítico textual de obras e autores de diferentes épocas dentro da nosa literatura, dende o século XVIII ata o momento actual