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Spinor norm for skew-hermitian forms over quaternion algebras
(Elsevier, 2015)
We complete all local spinor norm computations for quater-nionic skew-hermitian forms over the field Qof rational num-bers. This can be used to compute the number of classes in a genus of skew-hermitian lattices of rank ...
Calabi-Yau property for graded skew PBW extensions
(Universidad Nacional de Colombia - Sede Bogotá - Facultad de Ciencias - Departamento de Matemáticas - Sociedad Colombiana de Matemáticas, 2017-07-01)
Graded skew PBW extensions were defined by the first author as a generalization of graded iterated Ore extensions [36]. The purpose of this paper is to study the Artin-Schelter regularity and the (skew) Calabi-Yau condition ...
Shannon Entropy and Mutual Information for Multivariate Skew-Elliptical Distributions
(Wiley Publishing, 2013)
The entropy and mutual information index are important concepts developed by
Shannon in the context of information theory. They have been widely studied in the case of the
multivariate normal distribution. We first extend ...
A Bayesian semi-parametric approach to the ordinal calibration problem
(Taylor & Francis, 2016)
We introduce a semi-parametric Bayesian approach based on skewed Dirichlet processes priors for location parameters in the ordinal calibration problem. This approach allows the modeling of asymmetrical error distributions. ...
The role of core and strahlo electrons properties on the whistler heat-flux instability thresholds in the solar wind
(Frontiers Media, 2022)
There is wide observational evidence that electron velocity distribution functions (eVDF) observed in the solar wind generally present enhanced tails and field-aligned skewness. These properties may induce the excitation ...
Representation fields for quaternionic skew-hermitian forms
(Birkhäuser/Springer Basel AG, 2010)
Classes of indefinite quadratic forms in a genus are in correspondence
with the Galois group of an abelian extension called the spinor class
field (Estes and Hsia, Japanese J. Math. 16, 341–350 (1990)). Hsia has
proved ...
Robust mixture regression based on the skew t distribution
(Universidad Nacional de Colombia - Sede Bogotá - Facultad de Ciencias - Departamento de Estadística, 2017-01-01)
In this study, we propose a robust mixture regression procedure based on the skew t distribution to model heavy-tailed and/or skewed errors in a mixture regression setting. Using the scale mixture representation of the ...
Gelfand-kirillov dimension of skew pbw extensions
(Universidad Nacuional de Colombia; Sociedad Colombiana de matemáticas, 2013)
Gelfand-Kirillov dimension of Poincaré-Birkhoff-Witt (PBW for short) extensions was established by Matczuk ([15], Theorem A). Since PBW extensions are a particular example of skew PBWextensions (also called σ-PBW extensions), ...
A note on zip and reversible skew PBW extensions
(Universidad Nacional de Colombia - Sede Bogotá - Facultad de Ciencias - Departamento de Matemáticas, 2016-01-01)
In this note we establish necessary and sufficient conditions to guarantee the existence of zip and reversible skew PBW extensions.