Resumen

ZANDRON, Oscar P.. The fields ghost in the renormalization of Lagrangian t-J model. Nova scientia [online]. 2011, vol.3, n.6, pp.68-94. ISSN 2007-0705.

The present work treats the role of ghost fields in the renormalization procedure of the Lagrangian perturbative formalism of the t-J model. We show that by introducing proper ghost field variables, the propagator and vertices cam be renormalized to each order. In particular, the renormalized ferromagnetic magnon propagator coming from our previous Lagrangian formalism is studies in detail, and it is shown how the thermal softening of the magnon frequency is predicted by the model. The results are confronted with the previous one obtained by means of the spin-polaron theories.

Palabras llave : ghost fields; renormalization procedure; Lagrangian perturbative formalism; t-J model.