Main Question or Discussion Point
What would be today the open problems of Causal Dynamical Triangulations?
CDT today has many open problems which should mean it is relatively easy to get started in. there is not much prior literature to read eitherAlamino said:What would be today the open problems of Causal Dynamical Triangulations?
Chronos said:I think issues in CDT are not so much divergent as convergent. I realize this sounds naive, but isn't gauge invariance a bit problematical to begin with?
Maybe write to Dario Benedetti. he was at Rome "La Sapienza" for the Laurea and then went to Utrecht for PhD. seems like a friendly person from website and might have suggestionssAlamino said:... looking for problems in CDT. In truth, I'm will finish my PhD in Statistical Physics next month ...
my pleasure, hope something interesting works outAlamino said:...Thanks for the help.
...sounds like swirling surface tension and scaled bubble connections to me depending on whether the system is macro or micro given that bubbles always connect at trianglesmarcus said:it is What IS the CDT spacetime? For me that is the big OPEN PROBLEM that I wonder about. Because I do not think it looks like a differentiable manifold. But I think it is a real thing. there just is no usual familiar mathematical structure that we learn to use in grad school that corresponds to it. this is my suspicion.
As you go down smaller and smaller scale in CDT you get that space and spacetime both get more and more wrinkly and fractally and chaotic and frantically nonclassical, but it is always a topological CONTINUUM that gets wrinkly
Thanks SA, that was pretty deep. I have studied QFT, but am not very confident in my knowledge [which suggests I would be better off listening than posting]. I follow it pretty much to here:selfAdjoint said:In what way do you mean? Fadeev and Popov showed how to quantize gauge theories and 't Hooft and Veltman showed how to renormalize them, Becchi, Rouet, Stora, and also Tyutin (BRST) explained the ghost particles that Fadeev and Popov had found as due to a native supersymmetry that gauge field theories enjoy. The ghosts (scalar particles with Fermi-Dirac statistics) are not threatening; they are always off-shell and actually help to preserve unitarity. Do you regard any of this as problematical?
I went through that really excellent link and didn't see anything that suggested the author(s) found quantum gauge theories problematical. Could you specify?Chronos said:Thanks SA, that was pretty deep. I have studied QFT, but am not very confident in my knowledge [which suggests I would be better off listening than posting]. I follow it pretty much to here: