scholarly journals Extending the spin projection operators for gravity models with parity-breaking in 3-D

2010 ◽  
Vol 374 (34) ◽  
pp. 3410-3415 ◽  
Author(s):  
C.A. Hernaski ◽  
B. Pereira-Dias ◽  
A.A. Vargas-Paredes
Keyword(s):  
Gravity Models ◽  
Spin Projection ◽  
Projection Operators ◽  
Parity Breaking

scholarly journals Unitarity of Singh-Hagen Model in D Dimensions

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Elias L. Mendonça ◽  
R. Schimidt Bittencourt
Keyword(s):  
General Expression ◽  
Spin Projection ◽  
Projection Operators ◽  
Source Terms ◽  
Particle Content ◽  
Complete Set

The particle content of the Singh-Hagen model (SH) in D dimensions is revisited. We suggest a complete set of spin-projection operators acting on totally symmetric rank-3 fields. We give a general expression for the propagator and determine the coefficients of the SH model confirming previous results of the literature. Adding source terms, we provide a unitarity analysis in D dimensions. In addition, we have also analyzed the positivity of the massless Hamiltonian.

scholarly journals Higher derivative fermionic field equation in the first-orderformalism

2007 ◽  
Vol 85 (8) ◽  
pp. 887-897 ◽  
Author(s):  
S I Kruglov
Keyword(s):  
Dirac Equation ◽  
Spin Projection ◽  
Electromagnetic Current ◽  
Pure Spin ◽  
Projection Operators ◽  
Third Order ◽  
First Order ◽  
Generalized Dirac Equation ◽  
Electromagnetic Interactions ◽  
Higher Derivative

The generalized Dirac equation of the third order, describing particles with spin 1/2 and three mass states, is analyzed. We obtain the first-order generalized Dirac equation in the 24-dimensional matrix form. The mass and spin projection operators are found that extract solutions of the wave equation corresponding to pure spin states of particles. The density of the electromagnetic current is obtained, and minimal and nonminimal(anomalous) electromagnetic interactions of fermions are considered by introducing three phenomenological parameters. The Hamiltonian form of the first-order equation is obtained.PACS Nos.: 03.65.Pm, 11.10.Ef; 12.10.Kt

scholarly journals Hamiltonian analysis and positivity of a newmassive spin-2 model

2021 ◽  
Author(s):  
Alessandro Luiz Ribeiro dos Santos ◽  
Denis Dalmazi ◽  
Wayne Leonardo Silva de Paula
Keyword(s):  
Correlation Functions ◽  
Degrees Of Freedom ◽  
Spin Projection ◽  
Projection Operators ◽  
Gauge Invariant ◽  
New Model ◽  
Mixed Symmetry ◽  
Massive Spin ◽  
Rank 2 ◽  
Hamiltonian Analysis

Abstract Recently a new model has been proposed to describe free massive spin-2 particles in D dimensions in terms of a non symmetric rank-2 tensor eµν and a mixed symmetry tensor Bµ[αβ]. The model is invariant under linearized diffeomorphisms without Stueckelberg fields. It resembles a spin-2 version of the topologically massive spin-1 BF model (Cremmer-Scherk model). Here we apply the Dirac-Bergmann procedure in order to identify all Hamiltonian constraints and perform a complete counting of degrees of freedom. In D = 3 + 1 we find 5 degrees of freedom corresponding to helicities ±2, ±1, 0 as expected. The positivity of the reduced Hamiltonian is proved by using spin projection operators. We have also proposed a parent action that establishes the duality between the Fierz-Pauli and the new model. The equivalence between gauge invariant correlation functions of both theories is demonstrated.

scholarly journals Spin projection operators in (A)dS and partial masslessness

2020 ◽  
Vol 800 ◽  
pp. 135128
Author(s):  
Sergei M. Kuzenko ◽  
Michael Ponds
Keyword(s):  
Spin Projection ◽  
Projection Operators

scholarly journals New class of spin projection operators for 3D models

2012 ◽  
Vol 86 (10) ◽  
Author(s):  
Antonio Accioly ◽  
José Helayël-Neto ◽  
Bruno Pereira-Dias ◽  
Carlos Hernaski
Keyword(s):  
3D Models ◽  
Spin Projection ◽  
Projection Operators ◽  
New Class

scholarly journals Spin projection operators and higher-spin Cotton tensors in three dimensions

2019 ◽  
Vol 790 ◽  
pp. 389-395 ◽  
Author(s):  
Evgeny I. Buchbinder ◽  
Sergei M. Kuzenko ◽  
James La Fontaine ◽  
Michael Ponds
Keyword(s):  
Three Dimensions ◽  
Spin Projection ◽  
Projection Operators ◽  
Higher Spin

On the relativistic spin projection operators

1993 ◽  
Vol 43 (8) ◽  
pp. 777-782
Author(s):  
M. Bednář ◽  
P. Kolář
Keyword(s):  
Spin Projection ◽  
Projection Operators ◽  
Relativistic Spin

Determinants of Brazilian Exports by Levels of Technological Intensity: A Gravity Model Analysis Using the PPML Estimator

2019 ◽  
Vol 10 (9) ◽  
pp. 861-879
Author(s):  
Edson Roberto Vieira ◽  
◽  
Daniel Henrique Alves Reis ◽  
Keyword(s):  
International Market ◽  
Positive Influence ◽  
Gravity Models ◽  
Transport Costs ◽  
Consumer Market ◽  
Technology Products ◽  
The Us ◽  
Trading Partners ◽  
Negative Impacts ◽  
Technological Intensity

The objective of this study is to analyze the determinants of Brazilian exports by levels of technological intensity in the period 2000-2015. Gravity models were estimated for total of the exports and for each type of exports by levels of technological intensity, using the PPML-estimator. The study indicates that there is a process of concentration of Brazilian exports in low technology and medium-low technology products, at the same period in which China's share of total Brazilian shipments abroad grew. Estimates of empirical gravity models have shown that the income and size of the consumer market of Brazil’s trading partners seem to have the greatest positive influence on the Brazilian exports. Indications of this study are that the Brazil should continue to diversify its trading partners to minimize the impacts of a possible reduction of the economic growth of large trading partners (such as China and the US) on its exports and increase its exports of products with greater technological intensity. The results also highlight the need for Brazil to make greater efforts to increase its competitiveness in the international market to reduce the negative impacts of transport costs on the final prices of products exported by the country.

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