Note on the nonuniqueness of the massive Fierz-Pauli theory and spectator fields

It is possible to show that there are three independent families of models describing a massive spin-2 particle via a rank-2 tensor. One of them contains the massive Fierz-Pauli model, the only case described by a symmetric tensor. The three families have different local symmetries in the massless limit and can not be interconnected by any local field redefinition. We show here, however, that they can be related with the help of a decoupled and nondynamic (spectator) field. The spectator field may be either an antisymmetric tensor B μν=-Bνμ, a vector Aμ or a scalar field φ, corresponding to each of the three families. The addition of the extra field allows us to formulate master actions which interpolate between the symmetric Fierz-Pauli theory and the other models. We argue that massive gravity models based on the Fierz-Pauli theory are not expected to be equivalent to possible local self-interacting theories built up on top of the two new families of massive spin-2 models. The approach used here may be useful to investigate dual (nonsymmetric) formulations of higher-spin particles. © 2013 American Physical Society.

Peixoto's Theorem for vector fields on S2 with impasse points

The structural stability of vector fields with impasse regular curves on S2 is studied and a version of Peixoto's Theorem is established. Moreover a global analysis of normal forms of the constrained systems. A(x).ẋ=F(x),x∈R3,A∈M(3),F:R3→R3 in the Poincaré ball (i.e. in the compactification of R3 with the sphere S2 of the infinity) is made. © 2013 Elsevier Masson SAS.

OPF-MRF: Optimum-path forest and Markov random fields for contextual-based image classification

Some machine learning methods do not exploit contextual information in the process of discovering, describing and recognizing patterns. However, spatial/temporal neighboring samples are likely to have same behavior. Here, we propose an approach which unifies a supervised learning algorithm - namely Optimum-Path Forest - together with a Markov Random Field in order to build a prior model holding a spatial smoothness assumption, which takes into account the contextual information for classification purposes. We show its robustness for brain tissue classification over some images of the well-known dataset IBSR. © 2013 Springer-Verlag.

Development possibilities for small-scale industry in specific fields of industrial activity

Includes bibliography

Notas sobre el diagrama de Lexis

Las "Notas sobre el Diagrama de Lexis" forman parte del material docente del Curso de Mortalidad I del Programa de Maestria en Demografia y Estudios Sociales de Poblacion de CELADE 1985, y contiene 3 separatas: la descripcion del Diagrama de Lexis; un capitulo sobre representacion en el tiempo del libro Analisis Demografico de Pressat y el tema 1.2 Diagrama de Lexis del libro Tablas de Mortalidad de A. Ortega.

Rastros de velhos falares: léxico e cultura no vernáculo catalano

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The importance of Leptospira interrogans serovars Icterohaemorrhagiae and Canicola in coastal zone and in southern fields of Rio Grande do Sul, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Flag-dipole spinor fields in ESK gravities

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Invariance of quantum optimal control fields to experimental parameters

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Quantization of unstable linear scalar fields in static spacetimes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Quantum versus classical instability of scalar fields in curved backgrounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Functions and vector fields on C(CPn)-singular manifolds

Let M2n+1 be a C(CPn) -singular manifold. We study functions and vector fields with isolated singularities on M2n+1. A C(CPn) -singular manifold is obtained from a smooth manifold M2n+1 with boundary in the form of a disjoint union of complex projective spaces CPn boolean OR CPn boolean OR ... boolean OR CPn with subsequent capture of a cone over each component of the boundary. Let M2n+1 be a compact C(CPn) -singular manifold with k singular points. The Euler characteristic of M2n+1 is equal to chi(M2n+1) = k(1 - n)/2. Let M2n+1 be a C(CPn)-singular manifold with singular points m(1), ..., m(k). Suppose that, on M2n+1, there exists an almost smooth vector field V (x) with finite number of zeros m(1), ..., m(k), x(1), ..., x(1). Then chi(M2n+1) = Sigma(l)(i=1) ind(x(i)) + Sigma(k)(i=1) ind(m(i)).

Basin of attraction of a cusp-fold singularity in 3D piecewise smooth vector fields

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Orbit based procedure for doublets of scalar fields and the emergence of triple kinks and other defects

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)