ITMP Seminar "Losing the trace to discover dynamical Newton or Planck constants"

Dear Colleagues,

We are pleased to announce that the next ITMP seminar will be held on Wednesday, Apr 14, at 18:00 (Moscow time). The seminar will be arranged via Zoom. 

Speaker: Dr. Alexander Vikman, Institute of Physics of the Czech Academy of Sciences, Prague

Title: Losing the trace to discover dynamical Newton or Planck constants

Abstract: I will discuss our recent work e-Print: 2011.07055.  There we showed that promoting the trace part of the Einstein equations  to a trivial identity results in the Newton constant being an integration constant. Thus, in this formulation the Newton constant is a global dynamical degree of freedom which is also a subject to quantization, quantum fluctuations and the Heisenberg uncertainty relations.  This is similar to what happens to the cosmological constant in the unimodular gravity where the trace part of the Einstein equations is lost in a different way. I will consider a constrained variational formulation of these modified Einstein equations. Then, drawing on analogies with the Henneaux-Teitelboim action for unimodular gravity, I will discuss different general-covariant actions resulting in these dynamics. In this approach, it turned out that the inverse of the dynamical Newton constant is canonically conjugated to the Ricci scalar integrated over spacetime. Surprisingly, instead of the dynamical Newton constant one can formulate an equivalent theory with a dynamical Planck constant. Finally, I will show that an axion-like field can play a role not only of the cosmological constant, as in e-Print: 2001.03169, but also of the Newton constant or even of the Planck constant.

If you want to join the seminar please register here before 14:00, April 14.

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