Nonlinear electrodynamics and the gravitational redshift of highly magnetised neutron stars

Nota de FísicaPublicado

Herman J. Mosquera Cuesta; J. M. Salim

2004

Dados da publicação

Autores: Herman J. Mosquera Cuesta; J. M. Salim
Tipo: Nota de Física
Status: Publicado
Data de publicação: 2004
Descrição: We show that nonlinear electrodynamics (NLED) modifies in a fundamental basis the concept of gravitational red-shift (GRS) as it was introduced by Einstein's general relativity. The effect becomes apparent when light propagation from super strongly magnetized compact objects, as pulsars, is under focus. The analysis, here based on the (exact) nonlinear Lagrangean of Born \& Infeld (1934), proves that alike from general relativity (GR); where the GRS independs on any background magnetic ($B$) field, when NLED is taken into the photon dynamics an effective GRS appears, which happens to decidedly depend on the $B$-field pervading the pulsar. The resulting GRS tends to infinity as the $B$-field grows larger, as opposed to the Einstein prediction. As in astrophysics the GRS is admittedly used to infer the mass-radius relation, and thus the equation of state of a compact star, e.g. a neutron star (Cottam, Paerels \& Mendez 2002), this unexpected GRS critical change may misguide observers to that fundamental property. Hence, a correct procedure to estimate those valuous physical properties demands a neat separation of the NLED effects from the pure gravitational ones in the light emitted by ultra magnetised pulsars.
Ano: 2004
Número: CBPF-NF-023/04
Vínculo com tese: Não
Vínculo com bolsa: Não