New stuff happening in Quantum Gravity (a break-out in terminology at Sussex)
... school 15-16 September, to provide extra preparation for participants who wish it
Non-perturbative Methods in Quantum Field Theory
* Basics of lattice quantum gravity I (R. Loll, U Utrecht)
* Basics of lattice quantum gravity II (J. Barrett, U Nottingham)
Lately in QG papers I've seen the acronym LQG stand for Lattice QG and also for Lorentzian QG.
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for several years I've seen people who don't have much direct firsthand familiarity with QG research assuming that it was somehow mostly SPIN NETWORKS or else SPIN FOAMS. Spin networks are a characteristic tool of canonical Loop QG as it developed some 20 years ago. Then starting around 1996 quite a lot of the Loop people moved over and started working on Spinfoam approaches---different but conceptually related.
So Loops gets used as a generic catchall term. And the annual conference sometimes gets called Loops. Even though a lot of the research is NOT related to spin networks or even in a lot of cases to spinfoams.
I can imagine that a fair number of QG researchers are now impatient with this outdated terminology of putting what they do under the general rubric of Loops----when that misrepresents, and allows misconceptions to persist.
Furthermore LATTICE Quantum Gravity is a more accurate description. Laurent Freidel just translated the leading Spinfoam models into 4D lattice path integral formalism.
It looks like you can simply start with glued 4-simplices, and go all the way without ever making a detour into spinfoam (the 2-complex dual).
And LATTICE QG was what Ambjorn and Loll were doing all along.
It is not a regular lattice they work with, but it is made of 4-simplex cells glued together.
As long as you don't imagine the lattice as a repetitive boring one, then it is OK to think lattice.
So this looks to me terminology-wise like an organized jail-break. they want out from under the
Loops rubric. They want to fly a more accurately descriptive flag.
And one of the most successful areas of research that is actually bonafide Loop is the applied field LQC---loop applied to cosmology. And a lot of those papers are about what is called lattice-refinement. So we are all getting more lattice-conscious.
Plus Sussex included Thomas Thiemann, who does an evolved version of 1990s canonical Loop QG. So there is an all-inclusive tectonic plate movement in the works here. LQG is becoming Lattice QG.
The two-day school and the three-day conference/workshop are FREE. Any QG-minded person who is going to be in the UK in mid-September should consider seeing if you can still register. I think it is going to be a redefining event.
BTW notice the clever acronym CLAQG. Sounds like claque---I'd guess it's a Lollard pun. it contains LQG but avoids direct confrontation by spacing things out:
continuum and LATTICE approaches to QUANTUM GRAVITY...
Continuum and Lattice Approaches to Quantum Gravity
http://www.ippp.dur.ac.uk/Workshops/08/CLAQG
Among other things it will feature talks by
* Jan Ambjorn (NBI Copenhagen)
* John Barrett (U Nottingham)
* Laurent Freidel (ENS Lyon and Perimeter Institute)
* Renate Loll (U Utrecht)
* Max Niedermaier (U Tours)
* Roberto Percacci (SISSA Trieste)
* Martin Reuter (U Mainz)
* Thomas Thiemann (AEI Golm and Perimeter Institute)
You can see the emphasis
Triangulations Lattice people----Ambjorn, Loll
Asymptotic Safety Continuum people----Reuter, Percacci, Niedermeyer,
Spinfoam 4D Lattice---Freidel, Barrett
canonical LQG 3D Lattice---Thiemann