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The current understanding of our universe is built upon the information that we extract from light coming from cosmological sources like far‐away galaxies, quasars, supernovae, gamma‐ray bursts, etc, including the emission in radio wavelengths of those sources. The particular analysis of supernovae type Ia (SNIa) observations has led to the idea that the universe is undergoing a late‐time accelerate phase which started when it was at redshift z∼1. The redshift z is a cosmological parameter inferred from observations of emission (or absorption) lines from the expanding SNIa debris or from the supernova host galaxy, presuming the light properties and interactions, as described by Maxwell’s theory, do not change while it travels through the intervening intergalactic magnetic fields. In this paper we demonstrate that the nonlinear electrodynamics (NLED) description of photon propagation through the weak background intergalactic magnetic fields introduces a fundamental modification of the cosmological redshift...

Superluminal jet components are recurrently ejected from the core of active galactic nuclei (AGNs). The mechanism driving this powerful phenomenon is not properly understood yet. Here we suggest that the components ejection from AGNs may be related to the astrophysical process known as Bardeen‐Petterson (B‐P) effect, a general relativistic effect which forces a tilt (precessing) accretion disk orbiting a Kerr black hole (KBH) to break apart at the B‐P radius. This transition region hereby builds up a magneto‐centrifugal barrier which precludes incoming matter to penetrate the AGN inner disk or torus, and creates a sort of force‐free bridge or Lagrange internal point in a force‐free magnetosphere. (Inwardly pointing forces are counterbalanced by outwardly pointing forces). The material trapped in such a region will eventually find a condition of orbital resonance (beating) with the warps traveling along the torus due to its differential rotation. At resonance the mass blobs can be expelled from the B‐P radius in virtue of either the vertical (to the disk) linear momentum carried by the torus warps, or the Aschenbach effect in a nearly maximal KBH, or some other orbital resonances like the well known resonance 3:1. The launching of such superluminal components should produce powerful gravitational wave (GW) bursts during its early acceleration phase. These are GW signals that the LISA space‐borne GW observatory can detect for distances upto nearly the Hubble radius.

Quark matter is expected to exist in the interior of compact stellar objects as neutron stars or even the more exotic strange stars. Bare strange quark stars and (normal) strange quark‐matter stars, those possessing a baryon (electron‐supported) crust, are hypothesized as good candidates to explain the properties of a set of peculiar stellar sources. In this presentation, we modify the MIT Bag Model by including the electromagnetic interaction. We also show that this version of the MIT model implies the anisotropy of the Bag pressure due to the presence of the magnetic field. The equations of state of degenerate quarks gases are studied in the presence of ultra strong magnetic fields. The behavior of a system made‐up of quarks having (or not) anomalous magnetic moment is reviewed. A structural instability is found, which is related to the anisotropic nature of the pressures in this highly magnetized matter.

Quark matter is expected to exist in the interior of compact stellar objects as neutron stars or even the more exotic strange stars, based on the Bodmer‐Witten conjecture. Bare strange quark stars and (normal) strange quark‐matter stars, those possessing a baryon (electron) crust, are hypothesized as good candidates to explain the properties of a set of peculiar stellar sources as the enigmatic X‐ray source RX J1856.5‐3754, some pulsars as PSR B1828‐11 and PSR B1642‐03 (Xu 2003), and the anomalous X‐ray pulsars and soft gamma‐ray repeaters (Zhang et al. 2000). In the MIT bag model, quarks are treated as a degenerate Fermi gas confined to a region of space having a vacuum energy density Bbag (the Bag constant). In this note, we modified the MIT Bag Model by including the electromagnetic interaction. We also show that this version of the MIT model implies the anisotropy of the Bag pressure due to the presence of the magnetic field. The equations of state of degenerate quarks gases are studied in the presence of ultra strong magnetic fields. The behavior of a system made‐up of quarks having (or not) an anomalous magnetic moment is reviewed. A structural instability is found, which is related to the anisotropic nature of the pressures in this highly magnetized matter. The conditions for the collapse of this system are obtained and compared to a previous model of neutron stars build‐up on a neutron gas having anomalous magnetic moment.

We proposed in previous papers that variations in the kinematics of the parsec‐scale jet of some active galactic nuclei, as well as their long‐term periodic variability at optical wavelengths, are possibly related to the precession of their jet inlets. In this work, we study the feasibility of explaining its physical origin through rigid‐body precession of the accretion disc due to the misalignment between the angular momenta of the accretion disc and the Kerr black hole, as well as magnetic torques generated from the interaction between a large‐scale magnetic field and the induced electric currents in the disc.