Jul 5 – 10, 2021
Europe/Rome timezone


Conformal Dilaton Gravity and Related Issues

Jul 6, 2021, 9:30 AM


Conformal Dilaton Gravity and Related Issues: Block 1

  • Reinoud Slagter (ASFYON, Astronomisch Fysisch Onderzoek Nederland)


In the vicinity of the horizon of a black hole, curvature will be huge, so quantum effects will become important. Many attempts were made to construct a renormalizable and unitary quantum gravity model. For example, the effective field theory, where one ignores what is going on at high energy, or modified gravity models, where one loses unitarity. Further, just as in the Standard Model, one needs gauge-fixing terms as well as ghost fields. There is, however, a promising route to tackle these problems arising in quantum gravity. This model, conformal dilaton gravity, was initiated by ‘t Hooft. It is conjectured that conformal invariance is an exact symmetry and spontaneously broken, comparable with the Higgs mechanism. One writes the spacetime as g=omega^2.g’, where omega is the dilaton field, to be handled on an equal footing as the Higgs field and g’the “un-physical” spacetime. In constructing an effective action, one then first integrate over omega and afterwards over matter fields and g’. To overcome unitarity problems, the ingoing observer and the outside observers experience different omega, i. e., scales at which quantum effects becomes important. In fact, the dilaton is locally unobservable. It is fixed when one chooses the global spacetime and coordinate system. The complementarity of the Hawking radiation on the black hole spacetime, can be reformulated in connection with the information paradox .Other question that will come up for discussion: How will particles transmit the information they carry when crossing the horizon? Are they pure states or mixed states? What are the microstates of a black hole? Is there no inside by an antipodal map?
In this parallel session, all the issues mentioned above can be presented.

Presentation materials

Alessio Lapponi (UNICAM, University of Camerino. Quantum Optics & Quantum Information Group), Prof. Micheal Good (Department of Physics, Nazarbayev University, Kabanbay Batyr Ave 53, Nur-Sultan, 010000, Kazakhstan.)
7/6/21, 11:10 AM
Conformal Dilaton Gravity and Related Issues
Invited talk in the parallel session

Motivated by the fact that the null-shell of a collapsing black hole can be described by a perfectly reflecting accelerating mirror, we investigate an extension of this model to mirror semi-transparency and derive a general expression for the corresponding Bogoliubov coefficients. In so doing, we introduce the concept of ''impulsive accelerated mirrors", corresponding to those mirrors that...

Conformal Dilaton Gravity and Related Issues
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