The Shell Collapsar—A Possible Alternative to Black Holes
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 descripti...
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| Format: | Article |
| Language: | English |
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MDPI AG
2016-10-01
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| Series: | Entropy |
| Subjects: | |
| Online Access: | http://www.mdpi.com/1099-4300/18/10/363 |
| _version_ | 1818034980282957824 |
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| author | Trevor W. Marshall |
| author_facet | Trevor W. Marshall |
| author_sort | Trevor W. Marshall |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-10T06:47:47Z |
| format | Article |
| id | doaj.art-6eae369e455c4822a2e67e821be3bbbf |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-12-10T06:47:47Z |
| publishDate | 2016-10-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-6eae369e455c4822a2e67e821be3bbbf2022-12-22T01:58:37ZengMDPI AGEntropy1099-43002016-10-01181036310.3390/e18100363e18100363The Shell Collapsar—A Possible Alternative to Black HolesTrevor W. Marshall0Buckingham Centre for Astrobiology, The University of Buckingham, Buckingham MK18 1EG, UKThis 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.http://www.mdpi.com/1099-4300/18/10/363gravitational collapseOppenheimer-Snyderhorizonless solutionsneutron stars |
| spellingShingle | Trevor W. Marshall The Shell Collapsar—A Possible Alternative to Black Holes Entropy gravitational collapse Oppenheimer-Snyder horizonless solutions neutron stars |
| title | The Shell Collapsar—A Possible Alternative to Black Holes |
| title_full | The Shell Collapsar—A Possible Alternative to Black Holes |
| title_fullStr | The Shell Collapsar—A Possible Alternative to Black Holes |
| title_full_unstemmed | The Shell Collapsar—A Possible Alternative to Black Holes |
| title_short | The Shell Collapsar—A Possible Alternative to Black Holes |
| title_sort | shell collapsar a possible alternative to black holes |
| topic | gravitational collapse Oppenheimer-Snyder horizonless solutions neutron stars |
| url | http://www.mdpi.com/1099-4300/18/10/363 |
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