1,720,970 research outputs found
Decaimiento Raro del Muon Con un Modelo de Simetría Horizontal
No full textEn particulas elementales las masas de las particulas; fermiones y bosones, son generados al implementar un mecanismo llamado “Rompimiento Espontaneo de Simetria” (SSB). Las masas de los fermiones conocidos, quarks y leptones, son generados al romperse espontaneamente el grupo de simetria electrodebil U(1)Q de la “Electrodinamica Cuantica” (QED). En fisica de particulas elementales existe el llamado Modelo Estandar (SM) que ha tenido un enorme exito para describir cualitativamente y cuantitativamente la gran mayoria de los resultados experimentales encontrados ahora. Desde un punto de vista tecnico el SM implementa el SSB en el grupo de simetria electrodebil con la introduccion de un doblete de Escalares Fundamentales. Este mecanismo implica la existencia de una particula escalar neutra fisica que se le llama “Boson de Higgs”, el cual se le sigue buscando pero hasta ahora no se le ha encontrado
The Co-Evolution Between Galaxies and Dark Matter Halos
Full text linkThe current cosmological paradigm asserts that dark matter halos provide the
gravitational scaffolding for galaxy formation through a combination of
hierarchical structure formation and non-linear local (g)astrophysical
processes. This close relationship, known as the galaxy-halo connection,
suggests that the growth and assembly of dark matter halos impact the
properties of galaxies. While the stellar mass of galaxies correlates strongly
with the mass of their halos, it is important to note that the galaxy-halo
connection encompasses a broader distribution of galaxy and halo properties.
This distribution can be constrained using data from astronomical observations
and cosmological -body simulations, a technique known as semi-empirical
modeling. By operating at the intersection of observational data and the
cosmological structure formation model, the semi-empirical modeling provides
valuable insights into galaxy formation and evolution from a cosmological
perspective. In this proceeding, we utilize a new sEM-emPIRical modEl, EMPIRE,
to explore the star formation, SF, history of central galaxies across cosmic
epochs, spanning from dwarfs to massive ellipticals. EMPIRE aims to constrain
the multivariate distribution that links galaxy and halo properties. Our
findings reveal distinct growth stages for progenitors of central massive
galaxies. Evidence suggests that cold streams played a significant role in
sustaining SF at higher , while virial shock heating became more prominent
at lower . The maximum star formation efficiency, SFE, occurs at a factor of
below for . Furthermore, at
higher redshifts, , this peak tends towards higher masses, . Notably, at redshifts higher than
, the peak of SFE aligns comfortably within the region characterized by
cold streams.Comment: 16 pages, 7 figures. Extended contribution to the original proceeding
for the XVII Latin American Regional IAU Meetin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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