Encontrados 5 documentos, a visualizar página 1 de 1
Produção de gergelim orgânico nas comunidades de produtores familiares de São F...
QUEIROGA, V. de P.; GONDIM, T.M. de S.; VALE, D. G..; GEREON, H. G. M.; MOURA, J. de A.; SILVA, P. J. da; SOUZA FILHO, J.F. de.A cultura do gergelim (Sesamum indicum L.) constitui-se em alternativa de grande importância econômica e social para as condições semi-áridas do Nordeste brasileiro, por ser de fácil cultivo, apresentar tolerância a estiagem e, principalmente, por gerar renda e trabalho e por ser fonte de alimento para pequenos e médios produtores. As áreas do Semi-Árido do Nordeste brasileiro destacam-se como possuidoras de co...
Exploring the infrared gluon and ghost propagators using large asymmetric lattices
Oliveira,O.; Silva,P. J.We report on the infrared limit of the quenched lattice Landau gauge gluon propagator computed from large asymmetric lattices. In particular, the compatibility of the pure power law infrared solution (q²)²kappa of the Dyson-Schwinger equations is investigated and the exponent kappa is measured. The lattice data favours kappa ~ 0.52, which would imply a vanishing zero momentum gluon propagator as predicted by th...
A global optimization method for Landau gauge fixing in lattice QCD
Oliveira, O.; Silva, P. J.An algorithm for gauge fixing to the Landau gauge in the fundamental modular region in lattice QCD is described. The method, a combination of an evolutionary algorithm with a steepest descent method, is able to solve the problem of the nonperturbative gauge fixing. The performance of the combined algorithm is investigated on 84, [beta]=5.7, and 164, [beta]=6.0, lattice SU(3) gauge configurations. ; http://ww...
Gribov copies, lattice QCD and the gluon propagator
Silva, P. J.; Oliveira, O.We address the problem of Gribov copies in lattice QCD. The gluon propagator is computed, in the Landau gauge, using 302 ([beta]=5.8) 124 SU(3) configurations gauge fixed to different copies. The results of the simulation shows that: (i) the effect of Gribov copies is small (less than 10%); (ii)Â Gribov copies change essentially the lowest momenta components (q<2.6 GeV); (iii) within the statistical accuracy of...
Gribov copies and gauge fixing in lattice gauge theories
Oliveira, O.; Silva, P. J.We address the problem of the gauge fixing versus Gribov copies in lattice gauge theories. For the Landau gauge, results show that a suitable combination of evolutionary algorithms with traditional steepest descent methods identifies the global maximum of the optimisation function. We discuss the performance of the combined algorithm on small cubic lattices for SU(2) and SU(3). ; http://www.sciencedirect.com...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||