Past Events
June 2025 | |
| Tue 10 Jun 2025 14:00 - 15:00 |  Seminar: Spyros Alexakis from University of Toronto: Reconstructions of space-times from scattering data.Centre for Geometry, Analysis and Gravitation Title: Reconstructions of space-times from scattering data. Abstract: I address the problem of reconstructing space-times from measurements of their scattering data for suitable wave equations on the background geometry. For linear waves, the reconstruction allows one to reconstruct just the operator itself, assuming knowledge of the background geometry; moreover the best results deal with ``finite'' scattering, where measurements do no occur at infinity, but rather on a suitably long... |
| Mon 9 Jun 2025 | Curvature Flows Workshop Centre for Geometry, Analysis and Gravitation This one day workshop on Curvature Flows will take at Queen Mary University of London and features talks by international experts on mean curvature flow, Yamabe flow and curve shortening flow. |
| Wed 4 - Fri 6 Jun 2025 | Advances in Hyperbolic Problems Centre for Geometry, Analysis and Gravitation The aim of the workshop is to exchange the recent progress and ideas in the field of hyperbolic PDEs and its applications. This workshop brings together leading experts and young researchers to discuss the latest advances in hyperbolic problems,... |
| Tue 3 - Wed 4 Jun 2025 |  Gravitational Wave Initiative meeting 2025Centre for Geometry, Analysis and Gravitation The GWI at Queen Mary will host its second annual meeting on 03-04 June 2025. Following the success of last year's inaugural workshop and GWI lectures, this two-day event will have both colloquiuum-style talks and pedagogical lectures from leading experts in the field. There is no registration and all are welcome to attend. We will have a colloquium style talk by David Shoemaker (MIT) and one by Riccardo Sturani (ICTP - SAIFR) together with six pedagogical lectures from leading experts in... |
May 2025 | |
| Thu 29 May 2025 15:00 - 16:00 |  Seminar: Cosmological correlators in gravitationally constrained de Sitter states, Tuneer Chakraborty from Tata Institute of Fundamental Research (TIFR), MumbaiCentre for Geometry, Analysis and Gravitation Abstract : We study perturbative cosmological correlators in wavefunctionals which solve the Wheeler-DeWitt equation in asymptotically de Sitter spacetimes and were constructed in arxiv:2303.16315. Even in the G_N -> 0 limit, it is necessary to impose the gravitational Gauss law, which forces states to be de Sitter invariant. We set up Feynman rules for computing cosmological correlators in such states. We enumerate some necessary (but not sufficient) conditions that must be imposed on states... |
| Wed 28 May 2025 14:00 - 15:00 | Seminar: Phillipo Lappicy (Universidad Complutense de Madrid): Oscillatory spacelike singularities: The Bianchi type VI_{-1/9} vacuum models Centre for Geometry, Analysis and Gravitation The Bianchi type VI_{-1/9}, VIII and IX vacuum models all have 4-dimensional Hubble-normalized state spaces and are expected to have a generic initial oscillatory singularity, but the invariant boundary sets responsible for the oscillations are much more complicated for type VI_{-1/9} than those of type VIII and IX. For the first time, we explicitly solve the equations on these type VI_{-1/9} boundary sets and also introduce a new graphic representation of the associated network of heteroclinic... |
| Tue 27 May 2025 14:00 - 15:00 |  Seminar: GAnG seminar - Sadra Jazayeri - Uplifting Massive Graphs from Minkowski to de SitterCentre for Geometry, Analysis and Gravitation Identifying useful flat-space limits of cosmological correlators—defined on the future boundary of de Sitter space—is challenging due to their inherent scale invariance. In this talk, I present a massive flat-space limit in which cosmological correlators arising from the exchange of heavy fields can be expressed in terms of massive Feynman diagrams in Minkowski space. As a phenomenological application, I use this limit to compute the imprints of massive particles during inflation on... |
April 2025 | |
| Tue 15 Apr 2025 14:00 - 15:00 | Seminar: GAnG seminar - Molly Kaplan Centre for Geometry, Analysis and Gravitation Title - De Sitter quantum gravity and the emergence of local algebras Abstract - Quantum theories of gravity are generally expected to have some degree of nonlocality, with familiar local physics emerging only in a particular limit. Perturbative quantum gravity around backgrounds with isometries and compact Cauchy slices provides an interesting laboratory in which this emergence can be explored. In this context, the remaining isometries are gauge symmetries and, as a result, gauge-invariant... |
| Tue 1 Apr 2025 14:00 - 15:00 | Seminar: GAnG seminar - Betti Hartmann, Black holes and boson stars with wavy scalar hair Centre for Geometry, Analysis and Gravitation Black holes and boson stars with wavy scalar hair Static, spherically symmetric black holes can carry scalar hair when coupling standard Einstein gravity minimally to a self-interacting complex scalar field and a U(1) gauge field. For this scalar hair to exist, the frequency of the scalar field needs to be fine-tuned. In this talk, I will discuss these solutions and point out that for sufficiently large gravitational coupling, the space-time splits into two distinct parts: (a) an inflating... |
March 2025 | |
| Tue 25 Mar 2025 14:00 - 15:00 | Seminar: GAnG seminar - David Nielsen, Gravitational wave science in the next decade: a new frontier for numerical relativity Centre for Geometry, Analysis and Gravitation Gravitational wave science in the next decade: a new frontier for numerical relativity. The newly upgraded LIGO and Virgo observatories are regularly detecting gravitational waves from merging black holes and neutron stars, with public alerts for candidate events coming at a rate of about one per day. These observations provide new information about the population of black holes in the near universe, giving clues about their formation and history, and they allow us to test general relativity... |
| Tue 18 Mar 2025 14:00 - 15:00 | Seminar: GAnG seminar - Calvin Chen (rescheduled) Deformations of Extremal Black Holes Centre for Geometry, Analysis and Gravitation Title: Deformations of Extremal Black Holes Abstract: In this talk, I will re-examine a class of extremal charged black holes in AdS and study their EFT corrections. I will start by introducing static perturbations to the near-horizon geometry of extremal black holes. It turns out these generically suffer from singularities of various degrees. Particular deformations are marginal – they are not singular in GR, but even arbitrarily small EFT corrections seem to be able to make them... |
| Tue 11 Mar 2025 14:00 - 15:00 | Seminar: GAnG seminar - Christopher Couzens
Localising Romans Supergravity Centre for Geometry, Analysis and Gravitation Localising Romans Supergravity In this talk, I will discuss how Equivariant Localization can be used to compute observables in supergravity without the need to solve the equations of motion. We will use 6d Romans supergravity as our test case and show that the on-shell action is almost completely determined in terms of topological data. This allows us to recover known results in the literature and to make predictions for hitherto unknown solutions. |
February 2025 | |
| Tue 25 Feb 2025 14:00 - 15:00 | Seminar: GAnG seminar - Martin Taylor, Radiative properties of collisionless matter in isolated charged systems Centre for Geometry, Analysis and Gravitation Radiative properties of collisionless matter in isolated charged systems The Vlasov--Poisson system describes the evolution of an ensemble of either: 1. Electrically charged particles, interacting via an electrostatic Coulomb force; 2. Self-gravitating particles, interacting via a Newtonian gravitational force. In 3 space dimensions, for isolated systems, dispersive solutions asymptotically exhibit logarithmically corrected linear behaviour, i.e. such solutions ``scatter'' in a... |
| Tue 18 Feb 2025 14:00 - 15:00 | Seminar: GAnG seminar - Joshua Daniels Holgate Centre for Geometry, Analysis and Gravitation Title: Mean curvature flow from conical singularities Abstract: We discuss some regularity results for mean curvature flow from smooth hypersurfaces with conical singularities. We then discuss how to use these results to tackle the conical singularity resolution conjecture of Ilmanen, demonstrating a non-uniqueness dichotomy: a closed flow encountering a conical singularity 'fattens' if and only if the asymptotic cone also fattens. This is joint work with Otis Chodosh and Felix Schulze. |
| Tue 11 Feb 2025 14:00 - 15:00 | Seminar: GAnG seminar - Thomas Spieksma
Black hole environments: a landscape of possibilities Centre for Geometry, Analysis and Gravitation Title: Black hole environments: a landscape of possibilities Abstract: Black holes in our Universe are not expected to be in vacuum. Different black hole environments include accretion disks, dark matter spikes or superradiant boson clouds. In binary systems, these environments could be probed by future space-based gravitational wave interferometers. Understanding their impact is crucial--not only for detecting the gravitational wave signal in the first place but also for uncovering new... |
| Tue 4 Feb 2025 14:00 - 15:00 |  Seminar: GAnG seminar - Juan Valiente Kroon Inaugural Professorial Lecture
Asymptotics in General Relativity: the role of spatial infinityCentre for Geometry, Analysis and Gravitation Asymptotics in General Relativity: the role of spatial infinity In this overview talk I will discuss the relation between the asymptotic behaviour of the gravitational at null infinity and spatial infinity ¾the so-called problem of spatial infinity. I will argue that the conditions assumed by Penrose in his programme to study isolated systems in General Relativity are too restrictive to describe generic spacetimes. I will also discuss how a conformal approach to the study of the structure of... |
January 2025 | |
| Tue 21 Jan 2025 14:00 - 15:00 | Seminar: GAnG seminar - Lashi Bandara Centre for Geometry, Analysis and Gravitation Title: Harmonic analysis and boundary value problems in geometry Abstract: Historically, boundary value problems have appeared in engineering problems as partial differential equations on structures with boundary. However, in the past half century, differential operators have played a crucial role to encode, understand and resolve geometric and topological questions. This often requires the deformation of boundary conditions and harnesses index theory as a control mechanism through utilising... |