AdS/CFT without string theory

[marcus]

Could the correspondence be proven along the lines suggested by Laurent Freidel---one of the leaders in LQG research?

If you haven't heard of Freidel, there are two covariant LQG models currently being studied one being Rovelli et al, the other being Freidel et al's. He gave the invited LQG talks at the Paris 2009 Marcel Grossmann and the Sydney 2007 GR18 conferences.
That is to say if you are organizing a major international conference and you want one plenary speaker to describe current progress in LQG then you invite either Rovelli or Freidel.

So it might be interesting to see what tentative preliminary things Freidel has to say about AdS/CFT.

I was prompted to post this by Demystifier's comment in another thread:

Actually, maybe it is AdS/CFT that destroyed string theory (from the inside), because it turned out that AdS/CFT makes sense even without string theory, so many string theorists suddenly started to do AdS/CFT without doing string theory.
...

It is a simple but nevertheless observation that AdS/CFT makes sense without string. And is even perhaps provable in certain cases with other (nonstring) methods.

http://arxiv.org/abs/0804.0632
Reconstructing AdS/CFT
Laurent Freidel
34 pages
(Submitted on 4 Apr 2008)
"In this note we clarify the dictionary between pure quantum gravity on the bulk in the presence of a cosmological constant and a CFT on the boundary. We show for instance that there is a general correspondence between quantum gravity 'radial states' and a pair of CFT's. Restricting to one CFT is argued to correspond to states possessing an asymptotic infinity. This point of view allows us to address the problem of reconstructing the bulk from the boundary. And in the second part of this paper we present an explicit formula which gives, from the partition function of any 2 dimensional conformal field theory, a wave functional solution to the 3-dimensional Wheeler-DeWitt equation. This establishes at the quantum level a precise dictionary between 2d CFT and pure gravity."

 

[MTd2]

According to Padmanabhanh, http://arxiv.org/abs/1005.0619, GR is naturally Holographic! See Eq.(1). So, Verlinde's no gravity claim is what conceptually joins the above with Padmanabhanh.

 

[marcus]

I thought the basic idea of holography goes back to 1990s, and people like Bekenstein and Gerard 't Hooft.

You mentioned a 2005 paper of Padmanabhan. Padmanabhan is a good writer, I often like his papers. It's hard sometimes, though, to tell whether he is presenting a new idea, or is instead presenting an old idea in a new and interesting way.

I thing it was 't Hooft who first called it "holographic principle" (maybe in the mid 1990s?) but the idea was already around before it was named.

I recently had a look at a wonderful historical article by Hans Kastrup. (One of Heisenberg's PhD students, along with Felix Bloch and Edward Teller.)
Some incidental information here: http://en.wikipedia.org/wiki/Genealogy_of_theoretical_physicists
Here is Kastrup's historical article:
http://arXiv.org/abs/0808.2730.

Kastrup has a section on the history of AdS/CFT and cites this paper of Laurent Freidel that I mentioned.
He also cites several papers by Edward Witten. The AdS/CFT section is towards the end, see page 49.
Reference [245] is to Maldacena.
Reference [246] is to Witten.
Reference [247] is to three papers ( by Maldacena, by Nastase, and this one by Laurent Freidel.)

I'm curious as to why the Freidel paper has not been published. Did he not submit it?