There are AIs that do approximately average (amongst a select group of high achievers!) on high school math olympiad level questions. It does particularly well where things require formal proofs (its less good with geometry).
ChatGPT right now produces essays roughly at the first year...
A lot of anthropic predictions are posthoc. For instance, the value of the fine structure constant has to lie within a certain range for life and chemistry to be possible.
I am not aware of many examples where this was inverted to make a prediction. The only (kinda/sorta) exception that I...
Unimodular gravity is basically GR with the additional constraint that the determinant of the metric is enforced to be 1. I am not sure if there is a canonical reference of the theory perse, but it is often discussed in reviews on the cosmological constant problem. For instance Weinberg...
Or 99% classical curvature and 1% 'quantum' matter for emphasis with how things normally behave..
Note that before 1998, I would say the majority of physicists thought something like that was the case. The idea being that there was some mechanism that would zero the entire poorly defined <Tuv>...
Im picking up some confusions, so I thought I would briefly sketch a heurestic of the CC argument.
If you wish to quantize Einstein gravity, you need to come to grips with expectation values of the Einstein stress energy tensor. B/c even if gravity doesn't obey quantum mechanics, matter does...
Perhaps a simple measure might be to browse hep/th and hep/ph, derive a criteria for inclusion or exclusion (keywords perhaps) and then do a paper count?
I recommend reading one of the modern revisions of A Zee QFT in a nutshell. Not to learn, but to skim the relevant material (eg renormalization group). You can read the chapter in like an hour, understand the cartoon of what's going on, and then dive into the more technical material elsewhere...
There are known solutions that do this. Roughly one proceeds exactly as one might expect. Take the Kruskal extension of the usual black hole solution, and then glue a K = 1 FRW solution along the junction with the Einstein-Rosen bridge. Wheeler did this in the 60s, and they're sometimes known...
I think I follow. I will say there are a few different points of view about this sort of thing.. One point of view is to be a little careful with putting too much dogma into the absolute veracity of Penrose diagrams in quantum gravity. There has been a lot of work from the GR community going...
I don't quite know how to answer your first question. That requires detailed knowledge of bulk physics and a spacetime perspective that is seemingly absent from the calculations at this stage (at least I don't understand it). All they can say is that cutting up spacetime in exactly the way...
I don't think anyone really understands that. Certainly not for 4d Schwarschild. The actual 'state' of the spacetime is still very much a mystery in this business. What they have are entropy calculations and path integral calculations that give the 'plausibly correct' answer in 1+1d, but it's...
Hi Peter.
This research direction has been rather lively in the past year or so, and there are a lot of people working in this field. Indeed, the original papers derive the Page curve from first principles for the first time (something many didn't expect to see in our lifetimes) and then...
I had read a lot of concern about common core, but when I had to teach a lightning review of grade 8-12 to a family member to pass an equivalency test, I was pleasantly surprised. In my opinion, it’s a perfectly acceptable system and indeed even has many advantages over the old way.
My only...
You're guess about putting in the Planck Mass wasn't crazy, b/c that would be the naive yet natural scale to attempt to plug in for a reference system. And indeed the problem becomes manifest. Which is that
1) It is an intrinsically quantum regime, and so you have to make sense of that mess in...
Strictly speaking, one would need the notion of a dimensionless gravitational constant to really make sense of this question. Unfortunately this is actually quite subtle and gets into details of quantum gravity.
As mentioned before Newtons constant has natural units of inverse length...