In 1993, the Dutch Nobel prize-winning physicist Gerard t’Hooft suggested that all the information in a region of space can be represented as a hologram, an idea that implies that the laws of physics that govern our universe are somehow encoded on its (higher dimensional) boundary.
This idea, known as the holographic principle, has a certain elegance and so has received widespread attention from some theorists although nobody knowns whether it is a true description of the universe or not.
If it is true, Jae-Weon Lee from the Korea Institute for Advanced Study in Seoul and some pals, say that this boundary should emit Hawking radiation.
Hawking originally dreamt up this radiation idea to describe a process that might occur near the event horizon of a black hole. When pairs of virtual particles pop into existence (as they do all over the universe), they normally annihilate each other and disappear again. But near a black hole, one of these particles can cross the event horizon while the other makes its escape and this gives the impression that the black hole is emiting radiation.
Lee’s team say a similar thing may happen at the holographic boundary and that the energy this creates might be responsible for making the expansion of the universe accelerate.
They also explain why this radiation does not interact with ordinary matter and so is not seen in other ways: it’s wavelength, being universe-sized, is too long.
Seems as good an explanation as any other at this stage, after all the competition is ideas like quintessence, k-essence and quintoms.
Two things though: if this radiation exerts a force, why would it act to accelerate the expansion of the universe and not decelerate it? Lee and co are not convincing on this point. And, I wonder whether t’Hooft, who has some exotic ideas of his own about quantum determinism, would say that this kind of cosmic Hawking radiation is not compatible with the holographic principle and therefore bunkum.
Ref: arxiv.org/abs/0803.1987: Is Dark Energy from Cosmic Hawking radiation?