# What energy supports the existence of a black hole ???

## Are Black Holes Actually Dark Energy Stars?

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## Answer 1

July, 2021It depends on which black hole. Within the framework of the general theory of relativity (GR), a black hole is understood as a compact object bounded by an event horizon - a conditional surface, crossing which it is impossible to go back due to the peculiarities of the curved geometry of space-time under the horizon. From the point of view of general relativity, any space-time geometry is described by the solution of Einstein's equations. And there are solutions to these equations that describe black holes as pure geometry without any support from matter. More precisely: we are talking about vacuum solutions of Einstein's equations, where the so-called energy-momentum tensor of matter is equal to zero. These are the classic black holes of Schwarzschild, Reissner-Nordström, Kerr and others. So, in this sense, a black hole can be quite consistently presented as a pure effect of space-time geometry,

not requiringadditional energy support by any matter or radiation.Of course,

realblack holes as astrophysical objects formed as a result of the gravitational collapse of massive stars contain both their own stellar matter and particles and radiation falling from the outside. And all this matter, with its density, pressure and energy, somehow determines the geometry of the resulting object. Nevertheless, in order to maintain the event horizon (and thus for the existence of a black hole as such), the presence of any matteris not essential.In this way, black holes differ from the case

wormholes(in the English language literature referred to as wormhole - "wormhole"). Wormholes are also manifestations of a special space-time geometry, which have the character of tunnels between different regions of space. Such configurations are also solutions to Einstein's equations, but in order to maintain them in any realistic scenarios, they require the presence of specific (so-calledexotic) matter with negative energy density.