Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation

The magnetosphere structure of a magnetar is considered in the context of a theory of gravity with dynamical torsion field beyond the standard General Relativity (GR). To this end, the axially symmetric version of the Grad-Shafranov equation (GSE) is obtained in this theoretical framework. The resul...

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Publicado: 2019
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02198878_v16_n1_p_CiriloLombardo
http://hdl.handle.net/20.500.12110/paper_02198878_v16_n1_p_CiriloLombardo
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spelling paper:paper_02198878_v16_n1_p_CiriloLombardo2023-06-08T15:21:41Z Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation Grad-Shafranov equation Magnetar model Magnetosphere dynamics Non-Riemannian geometry The magnetosphere structure of a magnetar is considered in the context of a theory of gravity with dynamical torsion field beyond the standard General Relativity (GR). To this end, the axially symmetric version of the Grad-Shafranov equation (GSE) is obtained in this theoretical framework. The resulting GSE solution in the case of the magnetosphere corresponds to a stream function containing also a pseudoscalar part. This function solution under axisymmetry presents a complex character that (as in the quantum field theoretical case) could be associated with an axidilaton field. Magnetar-pulsar mechanism is suggested and the conjecture about the origin of the excess energy due the GSE describing the magnetosphere dynamics is claimed. We also show that two main parameters of the electrodynamic processes (as described in GR framework by Goldreich and Julian (GJ) [Astrophys. J. 157 (1969) 869]) are modified but the electron-positron pair rate remains invariant. The possible application of our generalized equation (defined in a non-Riemannian geometry) to astrophysical scenarios involving emission of energy by gravitational waves, as described in the context of GR in [S. Capozziello, M. De Laurentis, I. De Martino, M. Formisano and D. Vernieri, Astrophys. Space Sci. 333 (2011) 29-35], is briefly discussed. © 2019 World Scientific Publishing Company. 2019 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02198878_v16_n1_p_CiriloLombardo http://hdl.handle.net/20.500.12110/paper_02198878_v16_n1_p_CiriloLombardo
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Grad-Shafranov equation
Magnetar model
Magnetosphere dynamics
Non-Riemannian geometry
spellingShingle Grad-Shafranov equation
Magnetar model
Magnetosphere dynamics
Non-Riemannian geometry
Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation
topic_facet Grad-Shafranov equation
Magnetar model
Magnetosphere dynamics
Non-Riemannian geometry
description The magnetosphere structure of a magnetar is considered in the context of a theory of gravity with dynamical torsion field beyond the standard General Relativity (GR). To this end, the axially symmetric version of the Grad-Shafranov equation (GSE) is obtained in this theoretical framework. The resulting GSE solution in the case of the magnetosphere corresponds to a stream function containing also a pseudoscalar part. This function solution under axisymmetry presents a complex character that (as in the quantum field theoretical case) could be associated with an axidilaton field. Magnetar-pulsar mechanism is suggested and the conjecture about the origin of the excess energy due the GSE describing the magnetosphere dynamics is claimed. We also show that two main parameters of the electrodynamic processes (as described in GR framework by Goldreich and Julian (GJ) [Astrophys. J. 157 (1969) 869]) are modified but the electron-positron pair rate remains invariant. The possible application of our generalized equation (defined in a non-Riemannian geometry) to astrophysical scenarios involving emission of energy by gravitational waves, as described in the context of GR in [S. Capozziello, M. De Laurentis, I. De Martino, M. Formisano and D. Vernieri, Astrophys. Space Sci. 333 (2011) 29-35], is briefly discussed. © 2019 World Scientific Publishing Company.
title Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation
title_short Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation
title_full Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation
title_fullStr Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation
title_full_unstemmed Non-Riemmanian geometry, force-free magnetospheres and the generalized Grad-Shafranov equation
title_sort non-riemmanian geometry, force-free magnetospheres and the generalized grad-shafranov equation
publishDate 2019
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_02198878_v16_n1_p_CiriloLombardo
http://hdl.handle.net/20.500.12110/paper_02198878_v16_n1_p_CiriloLombardo
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