High Energy Physics Seminar next Thursday (Laurent Freidel)

[HECAP - Margherita Di Giovannantonio]

*_HIGH ENERGY PHYSICS SEMINARS_*
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*Thursday, 10 October* 2024, at *16:00* - *Luigi Stasi Seminar Room **- 
https://indico.ictp.it/event/10806/*
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Laurent Freidel (Perimeter Institute)


*“**Null Raychauduri: Canonical Structure, Dressing Time and Quantisation"*

_Abstract_
In this talk, I will review recent works done in collaboration with L. 
Ciambelli and R. Leigh, focusing on the non-perturbative 
characterization of the gravitational phase space along null boundaries. 
I will present the construction of the Carrollian curved geometry, the 
Poisson bracket and discuss the construction of  a field-dependent time 
called dressing time that allows the construction of a positive definite 
boost generator for expanding null surfaces.
If time permits, I will discuss some elements of the quantization and 
the appearance of a crucial Quantum central charge and the resolution of 
the problem of time. I will also discuss how these results connect to 
the celestial holography program when one treats the null boundary as an 
asymptotically null one.
I will only sketch why these results are important to address the 
upcoming interferometry experiments that are now being under 
construction to measure the light ray vacuum fluctuations.


*To join via Zoom*:
https://zoom.us/j/96460404622

Meeting ID: 964 6040 4622

Passcode: 204513

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