Speaker
Mr
Andrés F Gutierrez Ruiz
(Universidad de Antioquia)
Description
Frame dragging (Lense-Thirring effect) is generally associated with
rotating astrophysical objects.
However, it can also be generated by electromagnetic fields if electric
and magnetic fields are simultaneously present.
In most models of astrophysical objects, macroscopic charge neutrality
is assumed and the entire electromagnetic field is characterized in
terms of a magnetic dipole component.
Hence, the purely electromagnetic contribution to the frame dragging
vanishes.
However, strange stars may posses independent electric dipole and
neutron stars independent electric quadrupole moments that may lead
to the presence of purely electromagnetic contributions to the frame
dragging.
Moreover, recent observations have shown that in stars with strong
electromagnetic fields, the magnetic quadrupole may have a significant
contribution to the dynamics of stellar processes.
As an attempt to characterize and quantify the effect of electromagnetic
frame-dragging in this kind of astrophysical objects, an analytic
solution to the Einstein-Maxwell equations is constructed here on the
basis that the electromagnetic field is generated by the combination
of arbitrary magnetic and electric dipoles plus arbitrary magnetic
and electric quadrupole moments.
The effect of each multipole contribution on the vorticity scalar and
the Poynting vector is described in detail.
Corrections on important quantities such the innermost stable circular
orbit (ISCO) and the epicyclic frequencies are also considered.
Primary author
Mr
Andrés F Gutierrez Ruiz
(Universidad de Antioquia)
Co-author
Dr
Leonardo A Pachón
(Universidad de Antioquia)
