-
Natalia Gherghel (McMaster University)19/06/2026, 14:00Relativity, Gravitation and CosmologyContributed Talk
Minimal hypersurfaces are special because they are extrema of the area functional. They arise in various settings in mathematical physics. An important problem is to study their stability, that is, whether they are actually minima or saddle points (this means the surface can be deformed to one of smaller area). The problem reduces to finding the spectrum of the `stability operator' associated...
Go to contribution page -
Prof. Ariel Edery19/06/2026, 14:20Relativity, Gravitation and CosmologyContributed Talk
In this work, we find numerically static vortex solutions where the scalar and gauge fields have a non-singular profile under Einstein gravity in an AdS3 background. Vortices with different winding numbers n, VEV v and cosmological constant Λ are obtained. These vortices have positive mass and are not BTZ black holes as they have no event horizon. The mass is determined in two ways: by...
Go to contribution page -
Prof. Hari Kunduri (McMaster University, Mathematics and Physics)19/06/2026, 14:40Relativity, Gravitation and CosmologyContributed Talk
A foundational result of general relativity is that the positive mass theorem. This states that the ADM mass of an asymptotically flat initial data set is non-negative and vanishes if and only if the initial data embeds into Minkowski spacetime. I will discuss some recent work with A. Alaee and M. Khuri on extending this result to toric Riemannian manifolds with non-negative scalar curvature...
Go to contribution page -
Paul Fitzsimons (McMaster University)19/06/2026, 16:00Relativity, Gravitation and CosmologyContributed Talk
The spacetime geometry in a neighborhood of an extremal black hole (its near-horizon geometry) decouples from the exterior region. In Gaussian normal coordinates (GNC), the spacetime metric is completely fixed up to a function, a vector field and a metric on a horizon spatial cross-section. For non-extremal black holes, however, the geometry near the horizon does not decouple. We will...
Go to contribution page -
Antonia Seifert (Perimeter Institute & University of Waterloo)19/06/2026, 16:20Relativity, Gravitation and CosmologyContributed Talk
The initial-boundary value problem in general relativity has been the subject of extensive study. A central issue is the identification of boundary data and conditions on timelike boundaries that ensure well-posedness. In the work presented here, we approach the problem by considering perturbations of a background metric. We seek to disentangle the modes present in these perturbations,...
Go to contribution page -
Edward Wilson-Ewing (University of New Brunswick)19/06/2026, 16:40Relativity, Gravitation and CosmologyContributed Talk
The quantum field theory for a massless scalar field on a two-dimensional non-singular black hole spacetime gives a non-vanishing probability for a particle to tunnel out of the black hole. The black hole spacetime is non-singular, with an outer and an inner horizon, and the transition amplitude between a one-particle state localized inside the inner horizon, and a one-particle state localized...
Go to contribution page -
Kam To Billy Sievers (McMaster University)20/06/2026, 14:00Relativity, Gravitation and CosmologyContributed Talk
The outer-most marginally-outer trapped surface (MOTS) is often used as a quasi-local boundary of a black hole — the apparent horizon. During a black hole merger, the original two apparent horizons ultimately becoming one involves considerations of MOTSs at each time-slice, and strikingly reveals key involvement of self-intersecting MOTSs. Self-intersecting MOTSs have then been numerically...
Go to contribution page -
Lydia Taylor (University of Western Ontario)20/06/2026, 14:20Relativity, Gravitation and CosmologyContributed Talk
In linearized gravity there is a long-standing non-uniqueness problem regarding expressing the energy-momentum of the theory. Multiple distinct expressions exist in the literature, and there is not consensus which, if any, is the unique expression for the theory. Determining uniqueness is important as certain calculations require a unique expression. To address this problem, we use Noether’s...
Go to contribution page -
Sean Snider (Western University)20/06/2026, 14:40Relativity, Gravitation and CosmologyContributed Talk
Within the physics literature, there are multiple definitions of the energy-momentum tensor for Lagrangian field theories. The most common expressions are the ``canonical'' Noether formula, Hilbert's definition in terms of metric tensor derivatives, and Belinfante/Rosenfeld's improvement procedure. These definitions are not generally equivalent, but converge to the same result in cases such as...
Go to contribution page
Choose timezone
Your profile timezone: