Has any theory explained why does the void energy exists?

Void energy means vacuum energy, right?

In quantum theory vacuum is a state of the electromagnetic field, very similar to the state of the laser field.

If we measure the photon number of a laser field at any given moment, we find that the photon number is not fixed. Of course we will find an average number after some measuring.

Now for vacuum, we find that this average number is zero. And again we have fluctuations. This prediction can be verified with a photodetector attached to a vacuumized chamber.

We recognize that vacuum is not nothing. And this essentially is the origin of the phenomenon of pair creation.

These pairs can in principle be made detectable by breaking some symmetry. That is by an accelerating reference frame of the detector. This effect is the Unruh effect (cf. http://en.wikipedia.org/wiki/Unruh_Effect)

The measurement results in such an accelerated inertial frame will look like thermal black-body radiation. Interestingly the other way around, if such an accelerated detector is observed from another reference frame it comes out that it effectively emits(!) the same kind of radiation. So one photon goes in and the other goes out. This radiation signature could be detected using accelerated electrons since the angular distribution differs from the classical radiation distribution.

We have assumed photons as the mentioned particles. This is much easier since the photon is Matsubara particle, i.e. it is its own anti-particle.

Sorry, I can't answer this question, but something I've often wondered is, you burn kerosene and you're left with CO2 and water. You use uranium to generate heat in a nuclear reactor and you're left with a mixture of nuclear waste. If you extract the energy from a cubic metre of vacuum, what are you left with? Answers, anybody?

Dark Matter theory?

http://astro.berkeley.edu/~mwhite/darkmatter/essay...