Exact solutions of Brans-Dicke cosmology with decaying vacuum density

We investigate cosmological solutions of Brans-Dicke theory with both the vacuum energy density and the gravitational constant decaying linearly with the Hubble parameter. A particular class of them, with constant deceleration factor, sheds light on the cosmological constant problems, leading to a presently small vacuum term, and to a constant ratio between the vacuum and matter energy densities. By fixing the only free parameter of these solutions, we obtain cosmological parameters in accordance with observations of both the relative matter density and the universe age. In addition, we have three other solutions, with Brans-Dicke parameter w = -1 and negative cosmological term, two of them with a future singularity of big-rip type. Although interesting from the theoretical point of view, two of them are not in agreement with the observed universe. The third one leads, in the limit of large times, to a constant relative matter density, being also a possible solution to the cosmic coincidence problem.Comment: Minor changes, references added. Version accepted for publication in Classical and Quantum Gravit

Theater Studies in Creative Drama - A Journey of Transformation

The Theater Studies in Creative Drama project at UCF aimed to explore and implement Drama-Based Instruction (DBI) in education, with a specific focus on creating a lesson plan for children in hospitals. The project began by delving into the significance of play in childhood and its connection to theater. Through interdisciplinary collaboration with UCF nursing students, the team crafted a dynamic lesson plan, incorporating theatrical elements to enhance the educational experience for young patients. The To-Go Package, designed for children unable to attend in person, extended the impact of the project. The key activities involved reflection on personal experiences, connecting play to theater, understanding diversity, and communicating in diverse ways. Through this journey, I learned that DBI is a powerful tool for fostering creativity, communication skills, and empathy, transforming the traditional learning experience into a dynamic and inclusive educational approach.https://stars.library.ucf.edu/hip-2023fall/1078/thumbnail.jp

Les derniers écrits d’Adam Scot. Analyse linguistique et stylistique du «De quadripertito exercitio cellae». [Reseña]

Reseña de: Francesco PALLESCHI, Les derniers écrits d’Adam Scot. Analyse linguistique et stylistique du «De quadripertito exercitio cellae», Universität Salzburg («Analecta Cartusiana», 168), Salzburgo 2002, 199 pp

An early witness to the nature of the Canonical Order in the twelflh Century. A study in the life and writings of Adam Scot, with particular reference to his understanding of the Rule of St. Augustine. [Reseña]

Reseña de: David JONES, An early witness to the nature of the Canonical Order in the twelflh Century. A study in the life and writings of Adam Scot, with particular reference to his understanding of the Rule of St. Augustine, Universität Salzburg («Analecta Cartusiana», 151), Salzburgo 1999, 316 + VIII pp

Fundación y progresos de Ara Christi, convento de religiosos cartuxos. (Archivo Histórico Nacional de Madrid, Códices, 1.372 B). [Reseña]

Reseña de: Dom Juan Bautista GINER Y ARAGÓN, Fundación y progresos de Ara Christi, convento de religiosos cartuxos. (Archivo Histórico Nacional de Madrid, Códices, 1.372 B), edición crítica y transcripción de Albert Ferrer Orts, prólogo de Antonio Ballester Ballester, Universität Salzburg («Analecta Cartusiana», 196), Salzburgo 2003, 92 + XXXII pp

Past and Future of CG J1720-67.8: Constraints from Observations and Models

We discuss the evolution of the peculiar, nearby (z = 0.045), compact galaxy group CG J1720-67.8, by interpreting a large amount of observational information on the basis of our recent results from spectrophotometric evolutionary synthesis models and new N-body/SPH simulations. The group, that is composed of two spiral galaxies with a mass ratio approximately 4:1 and an S0 galaxy in a particularly compact configuration, is undergoing an active pre-merging phase. Several tidal features are signposts of the complex dynamics of the system. We suggest that the observed structure of the tidal features can be explained only if all three galaxies are involved in a strong interaction process.Comment: 5 pages, 3 (degraded) figures. Proc. ESO Workshop "Groups of galaxies in the nearby Universe", Santiago, Chile, 5-9 Dec. 2005, ESO Astrophysics Symposia, eds. I. Saviane, V. Ivanov & J. Borissova, Springer-Verla

The AMIGA sample of isolated galaxies: VIII. The rate of asymmetric HI profiles in spiral galaxies

(abridged) Measures of the HI properties of a galaxy are among the most sensitive interaction diagnostic at our disposal. We report here on a study of HI profile asymmetries (e.g., lopsidedness) in a sample of some of the most isolated galaxies in the local Universe. This presents us with an excellent opportunity to quantify the range of intrinsic HI asymmetries and provides us with a zero-point calibration for evaluating these measurements in less isolated samples. We characterize the HI profile asymmetries and search for correlations between HI asymmetry and their environments, as well as their optical and far infrared (FIR) properties. We use high signal-to-noise global HI profiles for galaxies in the AMIGA project (http://amiga.iaa.csic.es). We restrict our study to N=166 galaxies with accurate measures of the HI shape properties. We quantify asymmetries using a flux ratio parameter. The asymmetry parameter distribution of our isolated sample is well described by a Gaussian model. The width of the distribution is sigma=0.13, and could be even smaller (sigma=0.11) if instrumental errors are reduced. Only 2% of our carefully vetted isolated galaxies sample show an asymmetry in excess of 3sigma. By using this sample we minimize environmental effects as confirmed by the lack of correlation between HI asymmetry and tidal force (one-on-one interactions) and neighbor galaxy number density. On the other hand, field galaxy samples show wider distributions and deviate from a Gaussian curve. As a result we find higher asymmetry rates (~10-20%) in such samples. We find evidence that the spiral arm strength is inversely correlated with the HI asymmetry. We also find an excess of FIR luminous galaxies with larger HI asymmetries that may be spirals associated with hidden accretion events. Our sample presents the smallest fraction of asymmetric HI profiles compared with any other yet studied.Comment: 18 pages, 17 figures, accepted for publication in A&