A few items of different kinds:
- The Harvard Math department website has a wonderful profile of Dick Gross.
- The second International Congress of Basic Science ended a few days ago in Beijing. A huge number of interesting talks, video and slides available here. My Columbia colleague Richard Hamilton was one of the winners of a Basic Science Lifetime Award, unclear how much wealthier this makes him and his fellow awardees.
- Alphaxiv is a new website allowing for research discussion of arXiv papers.
- The Gates Foundation evidently is no longer going to pay publishing costs for open access journals. The problem is that this kind of funding incentivizes some sorts of bad publishing practices. They refer to
unsavory publishing practices by poor actors (paper mills, questionable quality review, unchecked pricing)
- The Perimeter Institute last week had a summer school on Celestial Holography. This panel discussion explains some of what the people involved are trying to do.
- Curt Jaimungal has been planning a series of programs on Rethinking the Foundations of Physics, with the topic “What is Unification?”. For the first program, featuring Neil Turok, see here. I’ll record something on Friday, part of the plan evidently is a lot of questions. If you have one, you can try leaving it as a comment and I’ll try and get some of them to Curt.
“Beautiful Math – Dick Gross”, National Museum of Mathematics, May 18, 2016
https://www.youtube.com/watch?v=SJSVPmOFYqg
Enjoyed the Turok discussion, and following Q&A. Thanks for the pointer!
Celestial holography and the related amplitudes and “modern S matrix” efforts appear to lean heavily on twistors, and attempt to find analogous connections between quantum gravity and a conformal field theory in flat spacetimes as is seen in AdS/CFT.
Turok, et al.’s theory is conformally invariant, makes use of Twistor Theory to formulate that, and equates (if I understood correctly) breaking of this conformal invariance with electroweak symmetry breaking.
Your own twistorial approach also seems quite different, with instead the breaking of spin group symmetry associated with the Higgs mechanism.
Unless I’ve badly misunderstood, Twistor Theory is not a model of quantum gravity, but a different way of describing space-time that might be more fundamental and better suited to theories of quantum gravity. In that regard, these three and other approaches utilizing twistors might have little otherwise to do with one another.
Then again, there might be deep connections between them. What do you think?
LMMI,
Twistors encode beautifully 4d spinors and 4d conformal symmetry and give a remarkable different way of thinking about space-time. A space-time point is by definition the spinor space at the point. This is going to appear naturally if you try and do anything with 4d conformal symmetry. So, not surprising the celestial holography people and Turok find twistor variables useful.
Since the beginning, the hope of people working on twistors has been that these are the right variables for quantum gravity. This works in a sense for a chiral version of gravity, not for the usual gravity which is thought of as parity invariant.
I’m pursuing a somewhat different version of this story, emphasizing the idea of looking not just at Minkowski spacetime twistors and Euclidean spacetime ones. Whether this has anything to do with these other programs, I don’t know, it’s not something I’m seeing indications of at the moment.
As a former journal associate editor, I found the announcement by the Gates Foundation that they would no longer pay APC’s (article processing charges) very interesting. I hope this is a trend. I think it is time to admit that gold open access has not worked. Its proponents, who were initially idealistic scientists but soon came to include government bureaucrats, claimed wonderful things for it. Among these were the claim that anyone could read the scientific papers for free thereby improving access (true) and that this would somehow decrease the amount of money going to large publishers (false). The money to pay the APC’s was supposed to come from the money institutions would save on subscriptions (at a cash-starved institution like CUNY this hope was laughable) and research grants. In regard to grants, not everyone has them, and the money that goes to pay APC’s is money that is not used to pay things like graduate student salaries. What happened is that you got bureaucrats mandating that papers be published in gold open access journals (see the EU’s Plan S), publishers adapting very nicely (the APC to publish in Nature is $12,290) and increasing the amount of money they made, and predatory journals sprouting up like mushrooms. It is time to go back to the drawing board, and refusing to fund APC’s is a step in the right direction.
Way back in 1978 I took calculus from Dick Gross. Even as a young assistant professor he was an excellent and engaging instructor, very good at adding historical motivations to his lucid explanations and letting his sense of humor come through.