As a star collapses, positions of its particles, as for any extended object, must be set on the hypersurfaces of simultaneity t = const., marked by world time moments t, i.e. ordinary astronomical time around a star. Then the surface of a dust star freezes over its gravitational radius and such asymptotic behaviour of the worldlines of star’s particles on the surface is invariant. The star’s center freezes before other layers, after which the entire structure of the star quickly freezes. This means that a specifically general relativistic phenomenon – gravitational time dilation – is the physical mechanism that stops the collapse in terms of t. Such freezing is shown for exactly solvable models. A thin shell freezes outside its gravitational radius, its interior remains flat, and the test particles inside also freeze. A homogeneous dust star, as shows the Oppenheimer-Snyder solution in terms t, becomes a frozen star or frozar. The inner layers remain locally homogeneous and freeze near their asymptotes. Before the freezing, sufficiently massive stars have a density below a neutron star and, therefore, if their nuclei have not exploded before, the collapse of such stars occur like a dust star with the frozar formation. The rotation of stars freezes even before the surface reaches the ergosphere boundary, so the rotated frozar has not a horizon and an ergosphere. Accretion to frozar leads to freezing of the falling matter above the surface with formation of an inhomogeneous landscape of flattened mascons. Frozars do not merge, but only stick together near the gravitational radius of the multifrozar system, by forming, together with ordinary matter, a frozar cluster. Supermassive frozars, or superfrozars, are formed mainly as such heterogeneous clusters. Frozars and their clusters are not “bald”, but may have a “hairstyle” and an asymmetric structure. The inhomogeneities of their field can be detected by gravimetry, inhomogeneities of shadows, redshifts and orbits of matter. Observational consequences and prospects of the frozar theory are discussed.
|QUANTUM AND GRAVITATIONAL PHYSICS |
1-006, 27p, 11.07.2020; doi:10.9751/QGPH.1-006.7132
|ISSN 2181-0486; EISSN 2181-0508|
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