I’ve been spending most of my time recently trying to get unconfused about Euclidean spinor fields, will likely write something here about that in the not too distant future. Some other things that may be of interest:
- I did an interview a couple days ago with Fraser Cain, who runs the Universe Today website. He had some excellent and well-informed questions about the state of HEP physics. I regret a little bit that I focused on giving an even-handed explanation of the arguments over a next generation collider, didn’t emphasize that personally I think building such a thing is a good idea (if the money can somehow be found), since the alternative would be giving up and abandoning this kind of fundamental science.
- On Monday, the Simons Center celebrated its 10th birthday, talks are here, giving a good overview of the kinds of math and physics that have been going on there during its first decade.
- For the latest on the formulation of the local Langlands correspondence in terms of the geometry of the Fargues-Fontaine curve, Peter Scholze is teaching a course now in Bonn, website here.
- Kirill Krasnov has a book out from Cambridge, Formulations of General Relativity. If you share my current interest in chiral formulations of GR and twistors, there’s a lot about these in the book. For a more general interest survey of what’s in the book, see Krasnov’s lectures last year at Perimeter (links and slides are on his website).
- A couple weeks ago, a very well-done explanation of what’s been going on around the black hole information paradox written by George Musser appeared at Quanta Magazine. Periodically in recent years I’ve tried to follow what’s up with this subject, generally giving up after a while, frustrated especially at not being able to figure out what underlying theory of quantum gravity was being studied. All that ever was clear was that this was about low-dimensional toy model calculations involving some assumptions that had ingredients coming from holography and AdS/CFT.
Musser’s article makes quite a few things clearer, with one striking aspect the news that:
researchers cut the tether to string theory altogether.
which I gather means that any foundation in AdS/CFT is gone, with what is being discussed now purely semi-classical. I don’t understand what these new semi-classical calculations are, and whether optimistic claims that the information paradox is on its way to a solution are justified (history hasn’t been kind to previous such claims). In recent years the pro-string theory research argument has often been that while there no longer were any prospects that it would tell us about particle physics, it was the best route to solving the problem of quantum gravity. It will be interesting to see what the effect will be of that cord getting cut by leading researchers.