Lorentzian Lie n-algebras

We classify Lie n-algebras possessing an invariant lorentzian inner product.Comment: 10 pages (V2: more details on Section 3 and a new lemma. V3: typos corrected

The big five: Discovering linguistic characteristics that typify distinct personality traits across Yahoo! answers members

Indexación: Scopus.This work was partially supported by the project FONDECYT “Bridging the Gap between Askers and Answers in Community Question Answering Services” (11130094) funded by the Chilean Government.In psychology, it is widely believed that there are five big factors that determine the different personality traits: Extraversion, Agreeableness, Conscientiousness and Neuroticism as well as Openness. In the last years, researchers have started to examine how these factors are manifested across several social networks like Facebook and Twitter. However, to the best of our knowledge, other kinds of social networks such as social/informational question-answering communities (e.g., Yahoo! Answers) have been left unexplored. Therefore, this work explores several predictive models to automatically recognize these factors across Yahoo! Answers members. As a means of devising powerful generalizations, these models were combined with assorted linguistic features. Since we do not have access to ask community members to volunteer for taking the personality test, we built a study corpus by conducting a discourse analysis based on deconstructing the test into 112 adjectives. Our results reveal that it is plausible to lessen the dependency upon answered tests and that effective models across distinct factors are sharply different. Also, sentiment analysis and dependency parsing proven to be fundamental to deal with extraversion, agreeableness and conscientiousness. Furthermore, medium and low levels of neuroticism were found to be related to initial stages of depression and anxiety disorders. © 2018 Lithuanian Institute of Philosophy and Sociology. All rights reserved.https://www.cys.cic.ipn.mx/ojs/index.php/CyS/article/view/275

On the structure of symmetric self-dual Lie algebras

A finite-dimensional Lie algebra is called (symmetric) self-dual, if it possesses an invariant nondegenerate (symmetric) bilinear form. Symmetric self-dual Lie algebras have been studied by Medina and Revoy, who have proven a very useful theorem about their structure. In this paper we prove a refinement of their theorem which has wide applicability in Conformal Field Theory, where symmetric self-dual Lie algebras start to play an important role due to the fact that they are precisely the Lie algebras which admit a Sugawara construction. We also prove a few corollaries which are important in Conformal Field Theory. (This paper provides mathematical details of results used, but only sketched, in the companion paper hep-th/9506151.)Comment: 19 pages, .dvi.uu (needs AMSFonts 2.1+

Supersymmetry and gauge theory on Calabi-Yau 3-folds

We consider the dimensional reduction of supersymmetric Yang-Mills on a Calabi-Yau 3-fold. We show by construction how the resulting cohomological theory is related to the balanced field theory of the Kaehler Yang-Mills equations introduced by Donaldson and Uhlenbeck-Yau.Comment: 11 page

A study of the Mg II 2796.34 A emission line in late--type normal, and RS CVn stars

We carry out an analysis of the Mg II 2796.34 A emission line in RS CVn stars and make a comparison with the normal stars studied in a previous paper (Paper I). The sample of RS CVn stars consists of 34 objects with known HIPPARCOS parallaxes and observed at high resolution with IUE. We confirm that RS CVn stars tend to possess wider Mg II lines than normal stars having the same absolute visual magnitude. However, we could not find any correlation between the logarithmic line width log Wo and the absolute visual magnitude Mv (the Wilson--Bappu relationship) for these active stars, contrary to the case of normal stars addressed in Paper I. On the contrary, we find that a strong correlation exists in the (Mv, log L) plane (L is the absolute flux in the line). In this plane, normal and RS CVn stars are distributed along two nearly parallel straight lines with RS CVn stars being systematically brighter by about 1 dex. Such a diagram provides an interesting tool to discriminate active from normal stars. We finally analyse the distribution of RS CVn and of normal stars in the (log L, log Wo) plane, and find a strong linear correlation for normal stars, which can be used for distance determinations.Comment: 10 pages, 7 figures, latex, to be published in A&