2016/10/12 by Trevor Marshall · 1 voice
Physics and Astronomy · #Astrophysics #Black hole (networking) #Classical mechanics #Compact star #Cosmology and Gravitation Theories #Equation of state #Gamma-ray bursts and supernovae #Gravitation #Gravitational collapse #Gravitational field #Mathematical physics #Neutron star #Physics #Pulsars and Gravitational Waves Research #Quantum mechanics #RADIUS #Schwarzschild radius #Stellar black hole #Theoretical physics
paper · pdf · doi:10.3390/e18100363
openalex publication_date 2016/10/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/22
This article argues that a consistent description is possible for gravitationally collapsed bodies, in which collapse stops before the object reaches its gravitational radius, the density reaching a maximum close to the surface and then decreasing towards the centre. The way towards such a description was indicated in the classic Oppenheimer-Snyder (OS) 1939 analysis of a dust star. The title of that article implied support for a black-hole solution, but the present article shows that the final OS density distribution accords with gravastar and other shell models. The parallel Oppenheimer-Volkoff (OV) study of 1939 used the equation of state for a neutron gas, but could consider only stationary solutions of the field equations. Recently we found that the OV equation of state permits solutions with minimal rather than maximal central density, and here we find a similar topology for the OS dust collapsar; a uniform dust-ball which starts with large radius, and correspondingly small density, and collapses to a shell at the gravitational radius with density decreasing monotonically towards the centre. Though no longer considered central in black-hole theory, the OS dust model gave the first exact, time-dependent solution of the field equations. Regarded as a limiting case of OV, it indicates the possibility of neutron stars of unlimited mass with a similar shell topology. Progress in observational astronomy will distinguish this class of collapsars from black holes.