Search results for "Application"
showing 10 items of 5559 documents
Cohomology of Filippov algebras and an analogue of Whitehead's lemma
2009
We show that two cohomological properties of semisimple Lie algebras also hold for Filippov (n-Lie) algebras, namely, that semisimple n-Lie algebras do not admit non-trivial central extensions and that they are rigid i.e., cannot be deformed in Gerstenhaber sense. This result is the analogue of Whitehead's Lemma for Filippov algebras. A few comments about the n-Leibniz algebras case are made at the end.
Discrete Abelian gauge symmetries and axions
2015
We combine two popular extensions of beyond the Standard Model physics within the framework of intersecting D6-brane models: discrete Zn symmetries and Peccei-Quinn axions. The underlying natural connection between both extensions is formed by the presence of massive U(1) gauge symmetries in D-brane model building. Global intersecting D6-brane models on toroidal orbifolds of the type T6/Z2N and T6/Z2xZ2M with discrete torsion offer excellent playgrounds for realizing these extensions. A generation-dependent Z2 symmetry is identified in a global Pati-Salam model, while global left-right symmetric models give rise to supersymmetric realizations of the DFSZ axion model. In one class of the lat…
Topics on n-ary algebras
2011
We describe the basic properties of two n-ary algebras, the Generalized Lie Algebras (GLAs) and, particularly, the Filippov (or n-Lie) algebras (FAs), and comment on their n-ary Poisson counterparts, the Generalized Poisson (GP) and Nambu-Poisson (N-P) structures. We describe the Filippov algebra cohomology relevant for the central extensions and infinitesimal deformations of FAs. It is seen that semisimple FAs do not admit central extensions and, moreover, that they are rigid. This extends the familiar Whitehead's lemma to all $n\geq 2$ FAs, n=2 being the standard Lie algebra case. When the n-bracket of the FAs is no longer required to be fully skewsymmetric one is led to the n-Leibniz (or…
T and CPT Symmetries in Entangled Neutral Meson Systems
2011
Genuine tests of an asymmetry under T and/or CPT transformations imply the interchange between in-states and out-states. I explain a methodology to perform model-indepedent separate measurements of the three CP, T and CPT symmetry violations for transitions involving the decay of the neutral meson systems in B- and {\Phi}-factories. It makes use of the quantum-mechanical entanglement only, for which the individual state of each neutral meson is not defined before the decay of its orthogonal partner. The final proof of the independence of the three asymmetries is that no other theoretical ingredient is involved and that the event sample corresponding to each case is different from the other …
Probabilistic whereabouts of the "quantum potential"
2011
We review major appearances of the functional expression $\pm \Delta \rho ^{1/2}/ \rho ^{1/2}$ in the theory of diffusion-type processes and in quantum mechanically supported dynamical scenarios. Attention is paid to various manifestations of "pressure" terms and their meaning(s) in-there.
Fitting formulae for photon spectra from WIMP annihilation
2011
Annihilation of different dark matter (DM) candidates into Standard Model (SM) particles could be detected through their contribution to the gamma ray fluxes that are measured on the Earth. The magnitude of such contributions depends on the particular DM candidate, but certain imprints of produced photon spectra may be analyzed in a model-independent fashion. In this work we provide the fitting formulae for the photon spectra generated by WIMP annihilation into quarks, leptons and gauge bosons channels in a wide range of WIMP masses.
Investigation of the effect of intensive milling in a planetary ball mill on the thermal decomposition of basic nickel carbonate
2011
The kinetics of thermal decomposition of basic nickel carbonate NiCO3Ni?(OH)2?nH2O and the effect of intensive milling in a planetary ball mill on its parameters, have been investigated. The values of the reaction heat and of the activation energy of thermal decomposition have been determined. Investigations of the thermal decomposition of the products of ball milling of investigated compound revealed a distinct effect of milling on the reaction temperature and heat consumed during the thermal decomposition of investigated compound.
Mechanisms of common ground in case-based web discussions in teacher education
2002
Previous studies suggest that before participants in web-based conferencing can reach deeper level interaction and learning, they have to gain an adequate level of common ground in terms of shared mutual understanding, knowledge, beliefs, assumptions, and presuppositions (Clark & Schaefer, 1989; Dillenbourg, 1999). In this paper, the purpose is to explore how participants establish and maintain common ground in order to reach deeper level interaction in case-based web discussions. The subjects in this study consisted of 68 preservice teachers and 7 mentors from 3 universities, who participated in a web-based conferencing course for 8 weeks. The written discussion data were analyzed by means…
Learner identity in EFL: An analysis of digital texts of identity in higher education
2018
This study explores learner identity (LI) in digital texts of identity (DTI) produced by college learners in English as a foreign language (EFL). In so doing, it aims to shed light on learners’ connections of their learning experiences across time and settings, and their impact on the various learner identities that form their LI. It also intends to elucidate how learners construct powerful learner identities in and through their digital discourses. To this end, 51 DTI were collected and scrutinized, following studies on LI, critical and poststructuralist discourse analysis, and “thematic” and “dialogic/performative” analysis within narrative research. Learners established connections betwe…
Deep and Meaningful E-Learning with Social Virtual Reality Environments in Higher Education: A Systematic Literature Review
2021
Deep and meaningful learning (DML) in distant education should be an essential outcome of quality education. In this literature review, we focus on e-learning effectiveness along with the factors and conditions leading to DML when using social virtual reality environments (SVREs) in distance mode higher education (HE). Hence, a systematic literature review was conducted summarizing the findings from thirty-three empirical studies in HE between 2004 (appearance of VR) and 2019 (before coronavirus appearance). We searched for the cognitive, social, and affective aspects of DML in a research framework and studied their weight in SVREs. The findings suggest that the use of SVREs can provide aut…