1,721,108 research outputs found
Scalar direct detection: In-medium effects
Full text linkA simple extension of the Standard Model consists of a scalar field that can potentially constitute the dark matter (DM). Significant attention has been devoted to probing light O(≲10eV) scalar DM, with a multitude of experimental proposals based on condensed matter systems as well as novel materials. However, the previously overlooked effective in-medium mixing of light scalars with longitudinal plasmons can strongly modify the original sensitivity calculations of the direct detection experiments. We implement the in-medium effects for scalar DM detection, using thermal field theory techniques, and show that the reach of a large class of direct DM detection experiments searching for light scalars is significantly reduced. This development identifies setups based on Dirac materials and tunable plasma haloscopes as particularly promising for scalar DM detection. Further, we also show that scalars with significant boost with respect to halo DM, such as those produced in the Sun, decay of other particles or by cosmic rays, will not suffer from in-medium suppression. Hence, multi-tonne direct DM detection experiments, such as those based on xenon or argon, also constitute a favorable target. We also discuss scalar mediated DM scattering
MeV sterile neutrinos in low reheating temperature cosmological scenarios
No full textIt is commonly assumed that the cosmological and astrophysical bounds on the mixings of sterile with active neutrinos are much more stringent than those obtained from laboratory measurements. We point out that in scenarios with a very low reheating temperature T-RH << 100 MeV at the end of (the last episode of) inflation or entropy creation, the abundance of sterile neutrinos becomes greatly suppressed with respect to that obtained within the standard framework. Thus, in this case cosmological bounds become much less stringent than usually assumed, allowing sterile neutrinos to be 'visible' in future experiments. Here, we concentrate on massive (mostly sterile) neutrinos with masses m(s) > 1 MeV for T-RH <= ms
Primordial black hole dark matter from catastrogenesis with unstable pseudo-Goldstone bosons
Full text linkWe propose a new scenario for the formation of asteroid-mass primordial black holes (PBHs). Our mechanism is based on the annihilation of the string-wall network associated with the breaking of a U(1) global symmetry into a discrete ZN symmetry. If the potential has multiple local minima (N > 1) the network is stable, and the annihilation is guaranteed by a bias among the different vacua. The collapse of the string-wall network is accompanied by catastrogenesis, a large production of pseudo-Goldstone bosons (pGBs) — e.g. axions, ALPs, or majorons — gravitational waves, and PBHs. If pGBs rapidly decay into products that thermalize, as predicted e.g. in the high-quality QCD axion and heavy majoron models, they do not contribute to the dark matter population, but we show that PBHs can constitute 100% of the dark matter. The gravitational wave background produced by catastrogenesis with heavy unstable axions, ALPs, or majorons could be visible in future interferometers
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
- …
