Résumé / Abstract Journal-club_GReCO

Séminaire / Seminar GReCO

« Signatures of quantum gravity with perfect fluid »

Harkirat Singh Sahota
Indian Institute of Science Education and Research Mohali (Mohali, Inde)

The canonical quantization of general relativity is riddled with issues at
the formal level, e.g., observables, the problem of time, choice of
ordering, etc. In the context of de-parameterized models (flat-FLRW model
with perfect fluid and dust shell collapse in quantum LTB geometry), we aim
to address these issues and investigate the signatures of quantum gravity.
The standard approach to incorporate the quantum gravity effects into the
semiclassical analysis is to adopt a `dressed metric' from the QG model
that represents the quantum-corrected regular spacetime. Since the relevant
observables are usually made out of conjugate variables that do not commute
in QG, the expectation value of only one variable might not suffice. The
viability of dressed metric-like approaches is investigated by comparing
the expectation value of a general class of ordering of these observables
with their dressed counterparts (expressions computed from metric
expectation). For the case of dust shell collapse in the quantum LTB model,
we study the mode decomposition of a unitarily evolving wave packet. For
the observable depicting mode decomposition, we identify incoming and
outgoing modes with the eigenstates of operator and estimate their
contribution to the radiation profile. The infrared sector of this process
demonstrates some characteristic features which turn out to be highly
sensitive to the near-bounce dynamics of the dust cloud.
vendredi 24 février 2023 - 14:00
Salle des séminaires Évry Schatzman
Institut d'Astrophysique de Paris
Pages web du séminaire / Seminar's webpage