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Alamino
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What would be today the open problems of Causal Dynamical Triangulations?
Alamino 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?
Alamino 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.
marcus 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?
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:
http://www.answers.com/topic/gauge-theory
CDT is a theory in theoretical physics that attempts to reconcile quantum mechanics and general relativity by studying the spacetime structure at the smallest scales.
Some of the open problems of CDT include understanding the emergence of spacetime from discrete building blocks, finding a consistent quantum theory of gravity, and explaining the observed deviations from classical spacetime at the Planck scale.
CDT differs from other theories of quantum gravity in its approach to discretizing spacetime and its focus on the causal structure of spacetime.
Current research efforts in CDT include studying the phase structure of the theory, investigating the emergence of classical spacetime, and exploring the connection to other theories of quantum gravity.
Solving the open problems of CDT could greatly advance our understanding of the fundamental nature of the universe, including the nature of space and time, and how gravity and quantum mechanics interact at the smallest scales.