Originally, I had an inclination to look at string theory as I was told that string theory is the only way to explain nature. When I asked what if its wrong, the string theorist I talked to explained that the contribution that it had made in mathematics is already so incredible that even if the whole thing turns out to be wrong its contribution would not go as a waste.(not a very satisfactory answer).I dont consider that I have reached the stage where I can declare to myself what is right and wrong. But I dont want to be a string theory fanatic (for that matter any theory) and hopefully be able to look at all the things with proper guidance.

I’m also trying to tackle this material on my own (even if it takes ten years). That is impressive you were able to do Polchinksi and Zwiebach. I took one look at Polchinksi and realized there were about six other subjects I had to learn first.

I wish you luck on your studies.
Mike

I wonder…have the Bogdanovs ever dared to give a
talk about their ’scientific work’ with experts as audience?
At a conference?

-drl

sounds very promising.
will you be blogging loop 05?

I will tell you what I think. You may look at the same bunch of researchers and see quite a different picture. In my view, (non-string) Quantum Gravity is a single research community and divsions within that are fairly fluid. Loll has written LQG papers, both Smolin and Markopoulou have written CDT papers. The spin foam sum over histories approach has some resemblance to the CDT path integral.

the people who do (nonperturbative background independent) Quantum Gravity are allied by having similar concerns and familiarity with each others’ methods—you might think of the different methods represented at the Loops 05 conference as a menu or as a repertory, and anyone who wants to do nonperturbative quantum gravity can choose from that menu of tactics.

Probably this year Loll’s new results will attract a lot of attention and the others will see if they can get similar results (with causal sets technique or spin foam) or if they can adapt CDT to what they do, or they will move over and try CDT approach proper.

Loll is just beginning to do black holes with CDT, and there are others who seem further along with that. Loll is also just beginning to include controlled topological variation in the path integral (so that it sums over topologies instead of just over the geometries of a fixed topology). People who use other methodology will want to know about that.

Collectively the (non-string) Quantum Gravity community is in a period of rapid growth, each year more people and more papers. I presume that will continue. I cant predict much about the demographic shifts WITHIN that community because people change back and forth and may even work several lines.

i read the links on loll’s CDT, and i see a claim is made it has a good semiclassical limit (unlike LQG, spin foam, etc)

while i understand LQG is based on asketar’s new variables quantized version of GR, it’s not clear to me how CDT starts and how it quantizes GR, what sort of predictions it makes at high energies/planck scale etc it seems clear to me it is unrelated to LQG.

do you think, given its good semiclassical limit, there will be an exodus from LQG and spin foams to CDT? (i.e smolin thiemann markapolou?)

can you enlighten me?