The Phantom Bounce: A New Oscillating Cosmology

An oscillating universe cycles through a series of expansions and contractions. We propose a model in which ``phantom'' energy with $p < -\rho$ grows rapidly and dominates the late-time expanding phase. The universe's energy density is so large that the effects of quantum gravity are important at both the beginning and the end of each expansion (or contraction). The bounce can be caused by high energy modifications to the Friedmann equation, which make the cosmology nonsingular. The classic black hole overproduction of oscillating universes is resolved due to their destruction by the phantom energy.Comment: Four pages, one figure. V3: version to appear in JCA

Prosociality and social responsibility. The case of students of a confessional University in Chile

Prosociality is of greater interest in recent decades due to events that have questioned the socially responsible behavior of decision-makers in various organizations. The objective of this research is to describe statistically significant differences in prosocial attitudes through sociodemographic characteristics among students at a confessional university in Chile. A quan-titative, descriptive, and non-experimental cross-sectional study was carried out. A non-probabilistic convenience sample of stu-dents of the last three years of studies at a confessional uni-versity located in south-central Chile was considered. The short scale of prosocial behavior was used, and a descriptive anal- ysis, exploratory factor analysis, and inferential analysis were performed. Prosocial attitudes are composed of three new di¬mensions, which are grouped according to the variables scale of prosocial behavior: comfort and commitment to others, empathy and detachment, and solidarity and help. Gender and religion stand out as statistically significant variables. Future research should consider a more diverse study group, including both de¬nominational and non-denominational universities. Likewise, it would be convenient to study the stability of prosocial attitudes throughout the life cycles and their relationship with other tran-scendent variables such as personality and self-efficacyLa prosocialidad es de gran interés en las últimas décadas debido a eventos que han cuestionado el comportamiento socialmente responsable de los tomadores de decisiones en diversas organizaciones. El objetivo de esta investigación es describir diferencias estadísticamente significativas en actitudes prosociales a través de características sociodemográficas entre estudiantes de una universidad confesional de Chile. Se realizó un estudio cuantitativo, descriptivo y no experimental de corte transversal. Se consideró una muestra no probabilística de conveniencia de estudiantes de los tres últimos años de carrera de una universidad confesional ubicada en la zona centro-sur de Chile. Se utilizó la escala corta de conducta prosocial y se realizó un análisis descriptivo, un análisis factorial exploratorio y un análisis inferencial. Las actitudes prosociales están compuestas por tres nuevas dimensiones, que se agrupan de acuerdo a las variables de la escala de comportamiento prosocial: comodidad y compromiso con los demás, empatía y desapego, y solidaridad y ayuda. El género y la religión destacan como variables estadísticamente significativas. Futuras investigaciones deberían considerar un grupo de estudio más diverso, incluyendo tanto universidades confesionales como no confesionales. Asimismo, sería conveniente estudiar la estabilidad de las actitudes prosociales a lo largo de los ciclos de vida y su relación con otras variables trascendentes como la personalidad y la autoeficacia.Incluye referencias bibliográfica

The Ultimate Fate of Life in an Accelerating Universe

The ultimate fate of life in a universe with accelerated expansion is considered. Previous work showed that life cannot go on indefinitely in a universe dominated by a cosmological constant. In this paper we consider instead other models of acceleration (including quintessence and Cardassian expansion). We find that it is possible in these cosmologies for life to persist indefinitely. As an example we study potentials of the form $V \propto \phi^n$ and find the requirement $n < -2$.Comment: 8 pages, RevTex. (V2 has a reference added, additional minor changes.

Longitudinal Homogenization of the Microbiome between Both Occupants and the Built Environment in a Cohort of United States Air Force Cadets

The microbiome of the built environment has important implications for human health and wellbeing; however, bidirectional exchange of microbes between occupants and surfaces can be confounded by lifestyle, architecture, and external environmental exposures. Here, we present a longitudinal study of United States Air Force Academy cadets (n = 34), which have substantial homogeneity in lifestyle, diet, and age, all factors that influence the human microbiome. We characterized bacterial communities associated with (1) skin and gut samples from roommate pairs, (2) four built environment sample locations inside the pairs’ dormitory rooms, (3) four built environment sample locations within shared spaces in the dormitory, and (4) room-matched outdoor samples from the window ledge of their rooms

CMBPol Mission Concept Study: Probing Inflation with CMB Polarization

We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high energy scale, and that the inflaton traversed a super-Planckian distance in field space. We explain how such a detection or constraint would illuminate aspects of physics at the Planck scale. Moreover, CMB measurements can constrain the scale-dependence and non-Gaussianity of the primordial fluctuations and limit the possibility of a significant isocurvature contribution. Each such limit provides crucial information on the underlying inflationary dynamics. Finally, we quantify these considerations by presenting forecasts for the sensitivities of a future satellite experiment to the inflationary parameters.Comment: 107 pages, 14 figures, 17 tables; Inflation Working Group contribution to the CMBPol Mission Concept Study; v2: typos fixed and references adde