Quantizing GR: Exact Quantum Loop Results in General Relativity

[selfAdjoint]

GR might be the answer. GR has accumulated a great deal of credibility via observational evidence. I do not object to string theory - only to theories that make no testable predictions.

I don't know what you're intending to contribute here, Chronos. Sauron's point is that this Ward result depends on GR being "asymptotically safe", which there is some evidence (challenged by Distler) for, and the recent work on supergravity suggests a possible noncontroversial variant to Ward's approach. But precisely because GR is what it is, it would be good if he could stay with it.

BTW I emailed Professor Ward yesterday, requesting some update, and we'll see what, if anything he says himself.

 

[MTd2]

Alright, I am summoning this thread from the dead. I hope all participants can join this again.

Ward took part in the Asymptotic Safety conference. Clearly, the other participants were not aware of his approach, not even Smolin. The impression I had of Ward it is that he is extremely clear. Carrasco was in disbelief because that was too good to be true. Weinberg took notes all the time, but didn't ask anything.

If Ward is wrong, well, no one there pointed out any.

Here is the link for the show:

http://pirsa.org/C09025

 

[ccdantas]

Alright, I am summoning this thread from the dead. I hope all participants can join this again.

Not entirely possible. At least one cannot join again; the owner of this thread is, unfortunately, deceased.

 

[marcus]

I hope all participants can join this again.

That would be possible (as far as I know) except in one case. selfAdjoint was one of the finest people I've ever known online.

His influence as PF mentor, and as a deeply thoughtful active participant, is one of the reasons PF is a great place. He died in 2007.

So we move on to the Asymptotic Safety conference the had this month at Perimeter.

Here is the link for the show:

http://pirsa.org/C09025

You and I already agreed that Ben Ward's paper seemed too good to be true. But the circumstances add respect and credibility. His got to talk on the first day. Percacci, the organizer, is very solid and he put Ward near the top of the line-up. Ward's presentation was convincing. He also sat through the other talks on all three days and was alert and asked questions in a calm friendly way. As you pointed out his background is places like Princeton and SLAC Stanford.

Circumstantially, everything looks good, so what's the "catch"?

 

[MTd2]

Oh, I am sorry. I didn't know he died. :S Damn, I FEEL SO EMBARRASSED.

I sent him an email 10 min ago. Here is the content. I hope he answers:

Dear Prof. Ward,

I watched you talk on the Asymptotic Safety, online:
http://pirsa.org/C09025
I was so impressed with your proof that I could not avoid to ask you a few questions.

You showed, during your talk, that you found a safe point in the UV, and that it should be related to other approaches like Reuter's and his collaborators. But do the connection to the A.S. of EQG (Einstein Quantum Gravity) beyond that? What I mean is, A.S. has a kind of space phase of parameters (/\, G) in which the sink point of the system is in ffact the UV fixed point of the theory, so can you show that your resume method also display a similar phase space? Can you also show similarities of the infinite coupling constants stabilizing around a finite dimension, like EQG?Thanks for reading my message.Best Regards,Daniel.

 

[cuallito]

I'm a physics undergrad with just one class to go. So forgive my if this is a dumb question. Is he just making a QM model for gravitational waves (by quantizing them into gravitons) or does it extend to crazy non-wavy, non-linear spacetimes?

 

[BigFairy]

crazy non-wavy, non-linear spacetimes is a little vague