4 ms·

> relatively far away from cosmology The preprint is in math.AP (Analysis of PDEs) alone. Most of the preprints by the three authors are found in math.AP, giv

> relatively far away from cosmology The preprint is in math.AP (Analysis of PDEs) alone. Most of the preprints by the three authors are found in math.AP, give or take some in math.CA (classical analysis & ODEs) and math.DG (diffgeo), with significant crossposting into math-ph and gr-qc. There is only a minority of <https://arxiv.org/list/gr-qc/new https://arxiv.org/list/gr-qc/new> that is crossposted into math.AP, but even fewer <https://arxiv.org/list/math.AP/recent https://arxiv.org/list/math.AP/recent> find themselves also in gr-qc. > Sad side note Amusingly, Alan Coley's [open problems in] "Mathematical General Relativity" <https://arxiv.org/abs/1807.08628 https://arxiv.org/abs/1807.08628> is only in gr-qc (§2.4 is relevant to the whole discussion here) and although he posts almost all his papers there, he is very much a mathematician <https://www.dal.ca/faculty/science/math-stats/faculty-staff/our-faculty/mathematics/alan-coley.html https://www.dal.ca/faculty/science/math-stats/faculty-staff/...>. (The earlier Chruściel, Galloway, Pollack "Mathematical general relativity: a sampler", citation [9] in Coley, <https://arxiv.org/abs/1004.1016 https://arxiv.org/abs/1004.1016> is in gr-qc, math.AP, and math.DG.) > (even many of those doing research in General Relativity) have never heard of mathematical GR Postdoc research? How did they avoid contact with mathematical GR? Hyper-hyper-specialization into an area where one diagonalizes almost as often as one breathes or spends all one's time in Cactus? If their shelves are surprisingly barren, they are liable to get thrown a copy of Wald, John M. Stewart (CUP 1991), and/or any of Choquet-Bruhat's books (esp. OUP 2008), and then Wald again.

codethief 4y ago
> Postdoc research? I obviously can't speak for everyone but, yes, at least it's been my impression that mathematical GR as a research field in mathematics is quite disconnected from physics and its existence, to some, completely unknown. Only very few people like Chruściel manage to bridge the gap and talk to and collaborate with people on both sides. To give a few data points: If you mostly do research on e.g. gravitational waves (think LIGO) you're usually far away from the typical geometric-analytical questions surrounding the foundations of GR and much more concerned with e.g. numeric simulations, elimination and modeling of noise and systematic errors, machine learning and such. Years ago, I talked to a professor in theoretical high-energy physics (mostly string theory / supergravity) and asked him for career advice because I wanted to do research on gravity and especially black holes. He told me that "GR as a research field is dead" and that, if I wanted to study black holes, there was "no way around string theory". Sure, he was probably biased and clearly living in a bubble relatively far away from "classic GR" but it still says a lot I would say. I mean even the people working on the Event Horizon Telescope don't know too much about mathematical/foundational questions in GR. They are much more interested in modeling and solving their specific problems, in this case: radioastronomical problems, problems in relativistic plasma physics etc. (Source: I have spoken to two leading scientists at the EHT about mathematical questions surrounding GR.)
- raattgift 4y ago
  I started and abandoned a couple of longer answers to this. What survives is a just pointer to <https://twitter.com/BHPToolkit https://twitter.com/BHPToolkit> / <https://bhptoolkit.org/users.html https://bhptoolkit.org/users.html> which I think undermines your SUGRA prof's advice and might lead you to reconsider whether "bridg[ing] the gap" is exceptionally rare.

codethief 4y ago

> Postdoc research? I obviously can't speak for everyone but, yes, at least it's been my impression that mathematical GR as a research field in mathematics is quite disconnected from physics and its existence, to some, completely unknown. Only very few people like Chruściel manage to bridge the gap and talk to and collaborate with people on both sides. To give a few data points: If you mostly do research on e.g. gravitational waves (think LIGO) you're usually far away from the typical geometric-analytical questions surrounding the foundations of GR and much more concerned with e.g. numeric simulations, elimination and modeling of noise and systematic errors, machine learning and such. Years ago, I talked to a professor in theoretical high-energy physics (mostly string theory / supergravity) and asked him for career advice because I wanted to do research on gravity and especially black holes. He told me that "GR as a research field is dead" and that, if I wanted to study black holes, there was "no way around string theory". Sure, he was probably biased and clearly living in a bubble relatively far away from "classic GR" but it still says a lot I would say. I mean even the people working on the Event Horizon Telescope don't know too much about mathematical/foundational questions in GR. They are much more interested in modeling and solving their specific problems, in this case: radioastronomical problems, problems in relativistic plasma physics etc. (Source: I have spoken to two leading scientists at the EHT about mathematical questions surrounding GR.)

raattgift 4y ago
I started and abandoned a couple of longer answers to this. What survives is a just pointer to <https://twitter.com/BHPToolkit https://twitter.com/BHPToolkit> / <https://bhptoolkit.org/users.html https://bhptoolkit.org/users.html> which I think undermines your SUGRA prof's advice and might lead you to reconsider whether "bridg[ing] the gap" is exceptionally rare.