Talk:Black Star (semiclassical gravity)

Differences

 * As I understand it:


 * Dark star (dark matter) - this type of dark star includes large amounts of dark matter, which the black star need not have. The density of this dark star is also much less than an ordinary star, and is dark, not because it is similar to a black hole, but simply because it doesn't generate much energy. It's a gas cloud that is prevented from collapsing further by thermal energy.


 * Dark star (Newtonian) - this type of dark star is a construct of Newtonian gravitation, and hence is not relativistic or conformant with quantum physics. It is essentially a Newtonian version of a black hole


 * Black star (semiclassical gravity) - this type of black star is a construct of semiclassical gravity, and therefore uses aspects of general relativity and quantum field theory to describe its characteristics.


 * Black hole - this type of stellar-derived object is a construct of general relativity, and is built without quantum physics in mind.


 * Fuzzball - this type of stellar-derived object is a construct of string theory, as an alternative to the relativisitic black hole. Everything under the radius of the equivalent event horizon is made of string matter, and the edge is not a sharp horizon, but a fuzzy surface, that breaks the information conservation paradox by allowing information to escape in a pseudo-Hawking radiation manner.


 * Eternally collapsing object - this type of stellar-derived object is derived from special relativity's limit on matter travelling faster-than-light, as the theorizers propose that to create a black hole, matter must exceed the speed of light to crash into the singularity. Instead, the speed limit means that an extremely dense layer, short of creating an event horizon is created, and is eternally collapsing toward the centre, with time slowed infinitely as it collapses.


 * Dark energy star - this type of stellar-derived object is derived from the mass-energy equivalency in relativity theory, by hypothesizing that matter is converted into vacuum energy as it crushes down towards the centre, thus the space within the event horizon in a different vacuum state, and having a higher energy, naturally wants to expand, the inflationary tendency cancels out the gravitational crush of the mass of the star, preventing the creation of a singularity. Since dark energy is frequently described as vacuum energy, that is the name of the concept star, because cosmological dark energy causes the universe to expand


 * Gravastar - this type of star uses Bose-Einstein Condensate as the form of matter created during collapse, and supporting pressure due to Planck level exclusions to the smooth spacetime of general relativity with quantized space and time (Planck length and Planck time)

76.66.197.30 (talk) 03:59, 26 September 2009 (UTC)