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
2010 ◽  
Vol 374 (34) ◽  
pp. 3410-3415 ◽  
Author(s):  
C.A. Hernaski ◽  
B. Pereira-Dias ◽  
A.A. Vargas-Paredes

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Elias L. Mendonça ◽  
R. Schimidt Bittencourt

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.


2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Yun-zhi Zou ◽  
Xi Li ◽  
Nan-jing Huang ◽  
Chang-yin Sun

A new class of generalized dynamical systems involving generalizedf-projection operators is introduced and studied in Banach spaces. By using the fixed-point theorem due to Nadler, the equilibrium points set of this class of generalized global dynamical systems is proved to be nonempty and closed under some suitable conditions. Moreover, the solutions set of the systems with set-valued perturbation is showed to be continuous with respect to the initial value.


2007 ◽  
Vol 85 (8) ◽  
pp. 887-897 ◽  
Author(s):  
S I Kruglov

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


Author(s):  
Alessandro Luiz Ribeiro dos Santos ◽  
Denis Dalmazi ◽  
Wayne Leonardo Silva de Paula

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.


2020 ◽  
Author(s):  
Amrita Chakrabarti ◽  
Monika Kaushik ◽  
Juveria Khan ◽  
Deepanshu Soota ◽  
P Kalairasan ◽  
...  

AbstractIn the post genomic era, tRNA-derived fragments have emerged as a new class of non-coding gene regulators, those play crucial roles both at the transcriptional and translational levels, in different cellular biogenesis. However, none of the studies has ever asked whether tRNAs can also be translated into peptides with any biological significance. Thus, we present a novel hypothesis which suggested that; design and synthesis of tRNA-derived peptides from prokaryotic genome can be exploited for developing unique chemotherapeutics against neglected tropical diseases, like Visceral leishmaniasis (VL) and its aggressive form known as post kalazar dermal leishmaniasis (PKDL). To achieve this aim, we have used a novel system biology-based strategy, which involved; i) mining of unique tRNAs from E. coli genome and their translation into peptide in silico, ii) designing of theoretical 3D models to evaluate their stability, iii) prediction of their biological activity by screening against anti-parasitic database to filter the lead peptide. Based on this strategy, a unique tRNA-derived peptide (tREP-18) was selected, chemically synthesized, and used in vitro for elucidating its therapeutic significance against L. donovani, a causative agent of VL and PKDL. Our findings demonstrated that, tREP-18 can impose high level toxicity to L. donovani promastigotes, by disrupting the ultrastructural cellular architect, destabilizing the mitochondrial membrane potential (ΔΨm), thus leading to drastic reduction in cell viability and proliferation. It also imparted high level of toxicity to BS12 a clinical isolate of PKDL. Conceivably, we for the first time reports a novel tRNA-derived peptide “tREP18” with excellent anti-leishmanial property, which can be further utilized for developing it as antileishmanial drug.One Sentence SummaryHere we report a novel first-in-class tRNA encoded peptide and its super anti-leishmanial characteristics.


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

2019 ◽  
Vol 790 ◽  
pp. 389-395 ◽  
Author(s):  
Evgeny I. Buchbinder ◽  
Sergei M. Kuzenko ◽  
James La Fontaine ◽  
Michael Ponds

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