Talk detail

Participant	Mosquera Cuesta, Herman J.
Institution	ICRANet / Universidade Estadual Vale do Acarau, Sobral, Brazil - Piazza della Repubblica 10 - Pescara - Pescara - Italy

Session	SF3	Accepted	No	Order	Time
Talk	Oral abstract	Title	Maximal electrically charged strange quark stars in nonlinear electrodynamics
Co-authors	Prof. Gaetano Lambiase
Abstract	Ultra strong electric fields can appear on the surface of the so called strange quark stars (Sq-Ss) provided they be electrically charged. The matter making up these stars is envisaged as of equal number of unconfined quarks with flavor up, down and strange (u, d, s). According to the Bodmer-Witten conjecture, quark matter is expected to exist in the interior of either neutron stars or in the hypothetized strange stars. In the MIT bag model, quarks are treated as a degenerate Fermi gas confined to a region of space having a vacuum energy density $B_{bag}$ (the Bag constant). Bare Sq-Ss and normal Sq-Ss (i.e., those possessing an electron-supported baryon crust) had been proposed as candidates to explain the properties of the puzzling X-ray source RX J1856.5-3754, canonical pulsars (PSR B1828-11, PSR B1642-03), anomalous X-ray pulsars and soft gamma-ray repeaters. Here we review the astrophysics of such hypothetized objects in the framework of nonlinear electrodynamics (NLED). It is shown that the dynamics expected in the MIT Bag Model is modified in virtue of the role played by the ultra strong nonlinear electric field on the Sq-Ss hydrodynamical equilibrium (equation of state), which drives a structural instability stemming from the surplus pressure of ultra electrically charged stars. (A similar phenomenon having been shown to occur in super strongly magnetized neutron stars). Such instability may drive Sq-Ss either to collapse or to reversing the gravity force direction producing big explosions which could explain the observational features of a class of gamma-ray bursts named short. Constraints on the parameters entering the NLED are obtained.

Session	SF2	Accepted		Order	Time
Talk	Oral abstract	Title	Maximal electrically charged strange quark stars in nonlinear electrodynamics
Co-authors	Prof. Gaetano Lambiase
Abstract	Ultra strong electric fields can appear on the surface of the so called strange quark stars (Sq-Ss) provided they be electrically charged. The matter making up these stars is envisaged as being of equal number of unconfined quarks with flavor up, down and strange (u, d, s). According to the Bodmer-Witten conjecture, quark matter is expected to exist in the interior of either neutron stars or in the hypothesized strange stars. In the MIT bag model, quarks are treated as a degenerate Fermi gas confined to a region of space having a vacuum energy density $B_{bag}$ (the Bag constant). Bare Sq-Ss and normal Sq-Ss (i.e., those possessing an electron-supported baryon crust) had been proposed as candidates to explain the properties of the puzzling X-ray source RX J1856.5-3754, canonical pulsars (PSR B1828-11, PSR B1642-03), anomalous X-ray pulsars and soft gamma-ray repeaters. Here we review the astrophysics of such theorized objects in the framework of nonlinear electrodynamics (NLED). It is shown that the dynamics expected in the MIT Bag Model is modified in virtue of the role played by the ultra strong nonlinear electric field on the Sq-Ss hydrodynamical equilibrium (equation of state), which drives a structural instability stemming from the surplus pressure of ultra electrically charged stars. (A similar phenomenon having been shown to occur in super strongly magnetized neutron stars). Such instability may drive Sq-Ss either to collapse or to reversing the gravity force direction producing big explosions which could explain the observational features of a class of gamma-ray bursts named short. Constraints on the parameters entering the NLED are obtained.