Variations Of Black Holes and Different Physical Properties
As intriguing as black holes are, just in their simplest forms, there are other phenomena related to them. Just as about anything else, they have their variations to them as well. All of these variations share the similarity of fundamentally being incredibly massive structures forming from a massive star collapsing on itself, A.K.A., a black hole. Variations arise, however, leading to different features and characteristics such as range of mass, possibly temperature, size, etc., and this leads to differing names and differences in expectations for the event horizon (Ionescu & Klainerman, 2008). A few examples include, mini black holes, Schwarzschild black hole, Kiselev and Dilaton black holes, and many more.
The phenomenon of mini black holes has gained popularity as type of an experiment on earth. This recent project is still very much under development and only an idea being debated, thus it is at a current halt for the time being. The idea suggests that “making mini black holes may be possible when the world’s largest particle accelerator — the Large Hadron Collider (LHC) — goes online outside Geneva, Switzerland” where “particles will smash together at nearly the speed of light, producing temperatures 100,000 times hotter than the core of the sun” in the new machinery, allowing for this project to advance (Landsberg, 2008). The debate arises in the problem concerning the black hole, in which there is fear that the black hole will go out of control, essentially ending all life on earth, but there is feedback to this and tells us that the black hole will die out before it is able to cause harm, as it will radiate away due to Hawking radiation. Hawking radiation shows an inversely proportional relation between size of the black hole and its temperature, and with more temperature, the more it radiates, thus a small one would radiate away incredibly fast (Landsberg, 2008).
Another type of black hole that can be seen is the Schwarzschild black hole. They are typically called the “moving Schwarzschild black holes” and can be observed for their thermodynamic properties, “identifying the temperature and entropy in a relativistic scenario” (Hinojosa & López-Sarrión, 2015). This type of black hole is to be analyzed with respect to an observer, and is carried out “by means of a Lorentz boost to the stationary solution,” allowing for the calculation of the geometrical temperature and analysis of the structure of the partition function (Hinojosa & López-Sarrión, 2015).
Kiselev and dilaton black holes are also examined. More specifically, their thermodynamics and phase transitions are examined. Values and quantities were able to be calculated, “relating the surface gravities, surface temperatures, Komar energies, areas, entropies, horizon radii, and the irreducible masses at the Cauchy and the event horizons” (Majeed et al., 2015). The product of the surface gravities, surface temperature, and Komar energies at the horizons weren’t universally applicable quantities for Kiselev black holes. For charged dilaton black holes however, all the projects just vanish, according to this article, (Majeed et al., 2015).
In terms of the event horizon, as seen by the external observer, “the region just outside the horizon, stretched horizon, acts like a hot membrane which absorbs, thermalizes, and emits and information that falls into the black hole,” and from the view “of a freely falling observer, there is nothing special at the horizon so a freely falling observer, can cross the horizon in his way to the singularity… no membrane, no stretched horizon, and nothing irregular at the event horizon” (Ge & Shen, 2005). Lastly from the view of the freely falling observer, all the information entering the black hole seems that it will never come back, with the black hole essentially engulfing everything (Ge & Shen, 2005).
Figure 1. Heat capacity undergoing phase transition from unstable to stable (Majeed et al., 2015).
Works Cited
Barrera Hinojosa, Cristian, and Justo López-Sarrión. “Moving Schwarzschild Black Hole And Modified Dispersion Relations.” Physics Letters B 749.(2015): 431- 436.
Ionescu, Alexandru D., and Sergiu Klainerman. “On The Uniqueness Of Smooth, Stationary Black Holes In Vacuum.” Inventiones Mathematicae 175.1 (2009): 35-102.
Majeed, Bushra, Mubasher Jamil, and Parthapratim Pradhan. “Thermodynamic Relations For Kiselev And Dilaton Black Hole.” Advances In High Energy Physics 2015.(2015): 1-11.
“The Menace Of Mini Black Holes.” Discover 29.8 (2008): 45-46.
Xian-Hui, Ge, and Shen You-Gen. “Relating Quantum Information To Charged Black Holes.” International Journal Of Modern Physics D: Gravitation, Astrophysics & Cosmology 14.8 (2005): 1321-1331.
