Workshop: New directions on classical and quantum gravity

12 déc. 2023, 09:00 → 13 déc. 2023, 18:00 Europe/Paris

Grand Amphithéâtre (LPSC)

mardi 12 décembre

09:30 → 11:00 Welcome coffee

11:00 → 11:30 Exploring non-linear gravitational waves in Horndeski gravity

Orateur: Jibril Ben Achour (LPENSL)

Talk-Marseille.pdf

11:30 → 12:00 Singularity-Free Spherical Black Holes with LQG corrections

I will present a family of spherical charged black holes in cosmological backgrounds which are solutions to an effective Hamiltonian with holonomy corrections motivated by loop quantum gravity.

Orateur: Asier Alonso (CPT)

ALONSO-BARDAJI.pdf

12:00 → 14:00 Lunch Break

14:00 → 14:30 Typical multipartite entanglement in large quantum systems - blackboard talk

Orateur: Sylvain Carrozza (IMB Dijon)

14:30 → 15:00 Quantum Gravity Projects: Symmetries, Spinfoams and Spin network Dynamics - blackboard talk

Blackboard talk

Orateur: Etera Livine (LPENSL)

15:00 → 15:30 Quasi-normal modes of LQG black holes

Orateur: Clara Montagnon (LPENSL)

Talk_Grenoble-2.pdf

15:30 → 16:00 Coffee break

16:00 → 16:30 Three puzzles in LQG (technical) - blackboard talk

Orateur: Simone Speziale (CPT)

16:30 → 17:00 New Wald-Zoupas charges for BMS

In this talk, I will construct new BMS charges which are able to measure some local energy flux on the celestial sphere. For this, I will introduce an edge mode, the supertranslation field, that has already been encountered in the literature. I will show that the new charges represent the BMS group, are covariant and independent on any choice of background structure, i.e choice of foliation or conformal factor. Furthermore, there is no cocycle or central extension in the representation of the algebra. I will check that these charges have all the properties required for an asymptotic notion of (local) energy on the celestial sphere.

Orateur: Antoine Rignon-Bret (CPT)

Presentation_Grenoble_final.pdf

mercredi 13 décembre

09:30 → 10:00 News from Grenoble

Orateur: Aurélien Barrau (LPSC)

10:00 → 10:30 Generalized holonomy corrections in effective LQC : Consistency and phenomenological consequences

Orateur: Maxime De-Sousa (LPSC)

pres.pdf

10:30 → 11:00 Coffee break

11:00 → 11:30 Fluid systems as gauge theories - blackboard talk

Orateur: Marc Geiller (LPENSL)

11:30 → 12:00 Light-cone thermodynamics

After introducing the main ideas behind light-cone thermodynamics, I will explicitly express the Minkowski vacuum of a massless scalar field in terms of the particle notion associated with suitable spherical conformal killing fields. These fields are orthogonal to the light wavefronts originating from a sphere with a radius of rH in flat spacetime: a bifurcate conformal killing horizon that exhibits semiclassical features similar to those of black hole horizons and Cauchy horizons of non-extremal spherically symmetric black holes. Our result highlights the quantum aspects of this analogy and extends the well-known decomposition of the Minkowski vacuum in terms of Rindler modes, which are associated with the boost Killing field normal to a pair of null planes in Minkowski spacetime (the basis of the Unruh effect).

Orateur: Salvatore Ribisi (CPT)

Grenoble2023.pdf

12:00 → 13:30 Lunch Break

13:30 → 14:00 Graviton corrections to Newton's potential as a test for non perturbative black hole models

On the one hand it is possible to determine graviton corrections to Newton's potential by treating GR as an effective field theory. On the other hand there are a multitude of quantum black hole models written as modifications of the Schwarzschild metric. I will show how it is possible to use these metrics to determine corrections to Newton's potential. I will show that in the case of the Hayward metric the corrections do not correspond to the graviton ones. Finally, I will present a generic method for testing whether a modified metric reproduces the graviton corrections to Newton's potential.

Orateur: Sami Viollet (CPT)

workshop grenoble.pdf

14:00 → 14:30 Noncommutative geometry and Quantum Gravity

Orateur: Valentine Maris (LPENSL)

grenoble_presentation.pdf

14:30 → 15:00 New elements on high frequency gravitational waves

Orateur: Killian Martineau (LPSC - Grenoble)

PBH-GWs-Martineau.pdf

UHFGWs-8-12-Martineau.pdf

15:00 → 16:00 Goodbye coffee