January 28, 2019 to February 1, 2019
Europe/Zurich timezone
There is a live webcast for this event.

Conformal symmetry as an exact symmetry with Higgs mechanism (TH colloquium)

Jan 30, 2019, 2:00 PM
4/3-006 - TH Conference Room (CERN)

4/3-006 - TH Conference Room


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Gerard 't Hooft


In theories such as asymptotically safe gravity, conformal symmetry is treated as a symmetry for the ultra-violet limit of quantum gravity. However, gravity can be formulated as a theory where conformal symmetry is exact, but broken in the same way as in the Brout-Englert-Higgs-Kibble formalism, where local gauge symmetry is still exactly valid but realised in an apparently asymmetric manner. This formally turns gravity into a renormalizable theory, except for the fact that a physically dubious particle emerges, a heavy excitation of the graviton with spin 2 but negative metric. It is not understood what exactly the role of such a particle would be, but it can be pointed out that, leaving this mystery as it is, does produce a scheme that is worth further study. It generates a system without any tuneable parameters, so it may be worth-while to investigate what the coupling parameters of such a theory would be, and check whether anything physically realistic can be produced. We must have matter added to the system, and the algebra will have to meet with rigorous constraints.

Presentation materials