Mathematical Physics of Gravity and Symmetry

Liste des Contributions

15. Integrability in the Dynamics of Binary Black Holes

Carlos Sopuerta (ICE-CSIC, IEEC)

19/11/2024 09:30

The scientific exploitation of gravitational wave observations depends strongly on the models of the signals that we use for their detection, mainly for binary black holes. These models, known as waveform models, are obtained from Einstein's equations (or their equivalent in alternative theories of gravity). The way of obtaining them is via different perturbative schemes and/or numerical...

8. Exploring the asymptotics of scalar fields near spatial infinity

Mariem Magdy (Instituto Superior Técnico)

19/11/2024 11:00

Conformal geometry tools allow us to study global geometric aspects of a spacetime using local differential geometry. In this talk, I will focus on a particular conformal representation of Minkowski spacetime which allows us to study the asymptotics of massless fields near spatial infinity. I will briefly discuss the analysis of the asymptotics of the wave equation in the context of this...

7. Integrable Hidden Structures in the Dynamics of Perturbed Black Holes

Michele Lenzi (ICE-CSIC)

19/11/2024 14:00

In this talk we discuss the presence of integrable hiddenstructures in the dynamics of perturbed non-rotating black holes (BHs). This can also be considered as a seed for a wider program of an effective identification of “slow” and “fast” degrees of freedom (DoFs) in the (binary) BH dynamics, following a wave-mean flow perspective. The slow DoFs would be associated with a nonlinear integrable...

4. Wilson Loops & Euclidean Wormholes

Panos Betzios (University of Gent)

19/11/2024 15:30

Euclidean wormholes are exotic types of gravitational solutions that still challenge our physical intuition and understanding. After reviewing universal properties of asymptotically AdS wormhole solutions from a gravitational (bulk) point of view and the paradoxes they raise, I will describe some concrete (microscopic) field theoretic setups and models that exhibit such properties. These...

1. Model spaces as constrained Hamiltonian systems

Glenn Barnich (Université libre de Bruxelles)

20/11/2024 09:30

Three dimensional gravity in Fefferman-Graham or BMS gauge is entirely described by the coadjoint representation of its asymptotic symmetry group. A group-theoretical attempt at quantization requires one to quantize not only individual but the whole collection of coadjoint orbits. This is where model spaces come in. We propose a definition of a model space for generic Lie groups in terms of...

6. Ti and Spi: extended boundaries at time- and spatial-infinity

Yannick Herfray (Université de Tours)

20/11/2024 11:00

13. Scattering of Dirac Fields in Black Hole Interiors

Milos Provci (University of Münster)

20/11/2024 14:00

Scattering problems in black hole interiors are an indispensable tool in the study of strong cosmic censorship. I will present joint work with M. Mokdad where we construct a scattering theory for the massive and charged Dirac field in the interior region of a sub-extremal Kerr-Newman(-anti)-de Sitter black hole. In this work, we show existence, uniqueness, and asymptotic completeness of...

3. Quasi-normal mode expansions of black hole perturbations: a hyperboloidal Keldysh’s approach

Jérémy Besson (AEI Hannover / Université de Bourgogne)

20/11/2024 14:30

We study asymptotic quasi-normal mode expansions of linear fields propagating on a black hole background, in order to achieve this we exploit the compactified hyperboloidal approach in order to cast quasi-normal modes as eigenfunctions of a non-selfadjoint problem and we adopt a Keldysh scheme for the spectral construction of resonant expansions. The role of the scalar product structure in the...

2. Memory effects from symmetries for a vacuum gravitational plane wave

Jibril Ben Achour (ENS Lyon / ASC LMU Munich)

21/11/2024 09:30

Memory effects are persistent modifications of relatives observables (relative distance, relative velocity, etc ...) between test particles induced by the passage of a gravitational wave. These radiative effects stand as ones of the last predications of general relativity yet to be confirmed. On the one hand, modeling these memory effects is crucial for developing accurate waveform templates...

12. An inflationary cosmology from Anti-de-Sitter wormholes

Olga Papadoulaki (CNRS, Ecole Polytechnique)

21/11/2024 11:00

There are various proposals as to what initial state can give rise to an inflationary cosmology. The two most popular ones are the no boundary (Hartle-Hawking) and the tunneling (Vilenkin) proposals. Both of them explain only part of the observations and lead to some paradoxes. In this talk, I will review these proposals and I will propose a novel initial state (wavefunction) of the universe...

14. Black hole perturbations in modified gravity as a first-order system

Hugo Roussille (ENS Lyon)

21/11/2024 14:00

The study of perturbations around a black hole is crucial for the investigation of stability of the solution, as well as the modelization of gravitational waves emitted during the ringdown phase of a binary black hole merger. In general relativity, such perturbations are recast into two decoupled Schrödinger equations; in modified theories of gravity, this is often no longer possible due to...

10. Lie-Poisson Equations: from Quantum Liquids to Gravity

Blagoje Oblak (CNRS, Université Claude Bernard Lyon 1)

22/11/2024 09:30

I argue that translation-invariant dynamical systems on Lie groups are ubiquitous in Nature. Numerous examples are provided, ranging from basic mechanics and hydrodynamics to the edge modes of topological insulators and quantum gravity. The geometric approach to such setups yields observables that are natural but surprisingly overlooked in the literature, notably including Berry phases that...

5. Null infinity and the black hole horizon: new conserved quantities from a geometric duality

Laura Donnay (SISSA)

22/11/2024 11:00

I will present a unified treatment for the boundary geometry of asymptotically flat spacetime and black hole horizons. This geometric duality implies an exact inversion isometry for extremal, non-rotating horizons, which will be used to relate and derive new infinite towers of conserved quantities. This is a work in collaboration with Shreyansh Agrawal and Panagiotis Charalambous.