Astrophysicists have found a new variety of space objects
The astrophysicists of the international scientific institute SISSA in Italy described a new class of space objects, by the force of gravity resembling black holes, but without a horizon of events. The final collapse of these stars is hampered by quantum effects. This is reported in a press release on the site Phys.org.
Scientists have proposed a mathematical model that combines the general theory of relativity with the effect of vacuum polarization. The latter consists in the fact that in empty space, due to the Heisenberg uncertainty principle, quantum fluctuations occur in the course of which vacuum "bubbles" are born and disappear - a particle-antiparticle pair. These particles are virtual, since they can exist only for a very short period of time and can not be registered with conventional devices. Thus, the appearance of particles from the "void" does not contradict the law of conservation of energy.
With external action, for example, from the side of the surrounding electromagnetic field, the virtual particles are reoriented so that particles with a positive charge are closer to the electron, which causes partial shielding of the electric charge. Such an effect can prevent the neutron star from contracting to the state of a black hole, even if its mass exceeds the Oppenheimer-Volkov limit.
The equilibrium of a neutron star is determined by gravity, and also by the pressure of a degenerate gas formed by densely packed neutrons. In the event that the gravitational attraction exceeds the repulsive force between neutrons, the star collapses into a black hole. Polarization of the vacuum creates an opportunity for the appearance of an intermediate form between neutron holes and neutron stars, which is called the quasiclassical relativistic star.