- Dark-energy star
-
A dark-energy star is a hypothetical compact astrophysical object, which a minority of physicists feel might constitute an alternative explanation for observations of astronomical black hole candidates. Dark energy is invisible to the human eye; however, it can be tracked with difficulty by gamma-ray astronomy.
The concept was proposed by physicist George Chapline. The theory states that infalling matter is converted into vacuum energy or dark energy, as the matter falls through the event horizon. The space within the event horizon would end up with a large value for the cosmological constant and have negative pressure to exert against gravity. There would be no information-destroying singularity.
Contents
Theory
In March 2005, physicist George Chapline claimed that quantum mechanics makes it a "near certainty" that black holes do not exist and are instead dark-energy stars. The dark-energy star is a different concept than that of a gravastar.
Dark-energy stars were first proposed because in quantum physics, absolute time is required; however, in general relativity, an object falling towards a black hole would to an outside observer seem to have time pass infinitely slowly at the event horizon. The object itself would feel as if time flowed normally.
In order to reconcile quantum mechanics with black holes, Chapline theorized that a phase transition in the phase of space occurs at the event horizon. He based his ideas on the physics of superfluids. As a column of superfluid grows taller, at some point, density increases, slowing down the speed of sound, so that it approaches zero. However, at that point, quantum physics makes sound waves dissipate their energy into the superfluid, so that the zero sound speed condition is never encountered.
In the dark-energy star hypothesis, infalling matter approaching the event horizon decay into successively lighter particles. Nearing the event horizon, environmental effects accelerate proton decay. This may account for high energy cosmic ray sources and positron sources in the sky. When the matter falls through the event horizon, the energy equivalent of some or all of that matter is converted into dark energy. This negative pressure counteracts the mass the star gains, avoiding a singularity. The negative pressure also gives a very high number for the cosmological constant.
Furthermore, 'primordial' dark-energy stars could form by fluctuations of space-time itself, which is analogous to "blobs of liquid condensing spontaneously out of a cooling gas." This not only alters the understanding of black holes, but has the potential to explain the dark energy and dark matter, that are indirectly observed.
See also
- Dark energy
- Stellar mass black hole
- Gravastar
References
- Merali, Zeeya (9 March 2006). "Three cosmic enigmas, one audacious answer". New Scientist: p. 8. http://www.newscientist.com/channel/fundamentals/mg18925423.600-three-cosmic-enigmas-one-audacious-answer.html.
- Musser, George (July 2003). "Frozen stars". Scientific American: pp. 20–21. http://www.scientificamerican.com/article.cfm?id=frozen-stars.
- Chapline, George (2005). Dark Energy Stars. arXiv:astro-ph/0503200. Bibcode 2005tsra.conf..101C.
- Barbieri, J.; Chapline, G. (2004). "Have Nucleon Decays Already Been Seen?". Physics Letters B 590 (1–2): 8–12. Bibcode 2004PhLB..590....8B. doi:10.1016/j.physletb.2004.03.054.
- Chapline, George; Hohlfeld, E.; Laughlin, R. B.; Santiago, D. I. (2003). "Quantum Phase Transitions and the Failure of Classical General Relativity". International Journal of Modern Physics A 18 (21): 3587–3590. arXiv:gr-qc/0012094. Bibcode 2003IJMPA..18.3587C. doi:10.1142/S0217751X03016380.
External links
- MPIE Galactic Center Research
- George Chapline (2005-03-28). "Black holes 'do not exist'". Nature News. http://www.nature.com/news/2005/050328/full/050328-8.html. (subscription only)
Star Evolution Formation · Pre–main sequence · Main sequence · Horizontal branch · Asymptotic giant branch · Dredge-up · Instability strip · Red clump · PG1159 star · Mira variable · Planetary nebula · Protoplanetary nebula · Luminous red nova · Luminous blue variable · Wolf–Rayet star · Supernova impostor · Supernova · Hypernova · Hertzsprung–Russell diagram · Color–color diagram
Protostars Molecular cloud (H II region) · Bok globule · Young stellar object · Herbig–Haro object · Hayashi track · Hayashi limit · Henyey track · Orion (T Tauri · FU Orionis) · Herbig Ae/Be
Luminosity class Subdwarf · Dwarf (Blue · Red) · Subgiant · Giant (Blue · Red) · Bright giant · Supergiant (Blue · Red · Yellow) · Hypergiant (Yellow) · Blue straggler
Spectral classification Remnants White dwarf (Black dwarf · Helium planet) · Neutron star (Pulsar · Magnetar) · Stellar black hole · Compact star (Quark · Exotic) ·
Stellar core: EF Eridani BFailed and
theoretical starsSubstellar object (Brown dwarf · Sub-brown dwarf · Planetar) · Boson star · Dark-matter star · Quasistar · Thorne–Żytkow object · Iron star
Nucleosynthesis Alpha process · Triple-alpha process · Proton-proton chain · Helium flash · CNO cycle · Lithium burning · Carbon burning · Neon burning · Oxygen burning · Silicon burning · S-process · R-process · Fusor · Nova (Remnants)
Structure Core · Convection zone (Microturbulence · Oscillations) · Radiation zone · Photosphere · Starspot · Chromosphere · Corona · Stellar wind (Bubble) · Asteroseismology · Eddington luminosity · Kelvin–Helmholtz mechanism
Properties Designation · Dynamics · Effective temperature · Kinematics · Magnetic field · Magnitude (Absolute) · Mass · Metallicity · Rotation · UBV color · Variability
Star systems Earth-centric
observation ofPole star · Circumpolar star · Magnitude (Apparent · Photographic · Color) · Radial velocity · Proper motion · Parallax · Photometric-standard star
Lists Star names · Arabic names · Chinese names · Most massive · Least massive · Largest · Brightest (Historical) · Most luminous · Nearest (Nearest bright) · Stars with exoplanets · Brown dwarfs · Planetary nebulae · Novae · Notable supernovae · Supernova remnants · Supernova candidates · Timeline of stellar astronomy
Related articles Planet · Star cluster · Association · Open cluster · Globular cluster · Galaxy · Supercluster · Helioseismology · Guest star · Constellation · Asterism · Gravity · Intergalactic star · Infrared dark cloud
Star portal Categories:- Black holes
- Stellar mass black holes
- Quantum gravity
- Star types
- Hypothetical stars
Wikimedia Foundation. 2010.