About every three years KEK issues a hype-filled press release announcing that Jun Nishimura and collaborators have used a supercomputer to get evidence for string theory. Back in 2008, the announcement was of a numerical simulation on a supercomputer of a supersymmetric QM system that supposedly showed that superstring theory explained the properties of black holes (press release here, preprint here, blogging here). In 2011, the claim was of a numerical simulation on a supercomputer that used superstring theory to understand the birth of our universe (press release here, preprint here, blogging here). Both of these papers were published in PRL.
The 2014 press release is now out (see here), based on this preprint from last December. The latest claim is that the authors have solved the black hole information paradox, have shown that we live in a hologram, as well as showing that string theory provides a self-consistent quantization of gravity, all by doing a numerical simulation of a QM system. Even better, they have made the quantum gravity problem just as well-understood and tractable as QCD:
In short, we feel that problems involving quantum gravity have become as tractable as problems involving the strong interaction. The latter can be studied by simulating a gauge theory on a four-dimensional (4D) lattice, and such a method has recently been used to reproduce the mass spectrum of hadrons (28) and the nuclear force (29). We can now apply essentially the same method to study quantum gravity, which has been thought to be far more difficult.
This latest version of the KEK-hype has gotten a lot more attention than the previous two versions. Based on the preprint, late last year for some reason Nature covered this with a story about how Simulations back up theory that Universe is a hologram and this got a lot of media attention (see here for example).
The paper has now been published, and this time it’s not in PRL, but in Science magazine (submission there was a month after the preprint came out, could it be that PRL wouldn’t have it?). Science is giving it a high profile, including together with it a piece by Juan Maldacena, which claims the paper as “further evidence of the internal consistency of string theory”. Science provides the following one-line summary of the Maldacena piece:
A numerical test shows that string theory can provide a self-consistent quantization of gravity.
One obvious problem with this is that even if you take the most optimistic view of it all, what is being described is quantum gravity in 10d space-time. The Japanese authors deal with this problem with a footnote:
Theoretical consistency requires that superstring theory should be defined in ten-dimensional space-time. In order to realize our four-dimensional space-time, the size of the extra six dimensions can be chosen to be very small without spoiling the consistency.
Remarkably, Maldacena has another answer: the multiverse, which now he seems to take as accepted fact.
Of course, the 10-dimensional space under consideration here is not the same as the four-dimensional region of the multiverse where we live. However, one could expect that such holographic descriptions might also be possible for a region like ours.
Absurd hype about string theory is a continuing problem, and it’s not one that can be blamed on journalists, with this latest example getting help from HEP lab press releases, a highly reputable journal, and an IAS faculty member.