9 papers
Comparing twist-free axisymmetric gravitational waves near the black hole threshold
Ananya Adhikari, Tomáš Ledvinka, Daniela Cors +4
The threshold of black hole formation in axisymmetric vacuum gravity is proving to be more complicated than had been anticipated but, following recent advances, a consensus between…
Starting inflation in asymptotically flat spacetimes
Sam E. Brady, Thomas W. Baumgarte, Katy Clough
A key question in early universe cosmology is whether inflation can be successfully seeded by a generic, localised fluctuation in the inflaton field that probes the inflationary pa…
Primordial Black Holes in a Radiation-Dominated Universe
Thomas W. Baumgarte, Katy Clough, Mary Gerhardinger +2
Primordial fluctuations frozen out during inflation re-enter the cosmological horizon and can collapse, leading to the formation of primordial black holes. We perform simulations o…
Critical collapse of vacuum spacetimes: Nakamura wave initial data
Thomas W. Baumgarte, Carsten Gundlach, David Hilditch
We report on numerical simulations of critical phenomena in the collapse of axisymmetric vacuum gravitational waves, adopting families of initial data that, to the best of our know…
Subsolar mass black holes from stellar collapse induced by primordial black holes
Thomas W. Baumgarte, Stuart L. Shapiro
While no gravitational-wave detection of subsolar mass black holes has been confirmed to date, a number of candidate detections invite us to speculate on the origin of such black h…
Restrictions on Initial Conditions in Cosmological Scenarios and Implications for Simulations of Primordial Black Holes and Inflation
Thomas W. Baumgarte, Katy Clough, John T. Giblin
Numerical relativity simulations provide a means by which to study the evolution and end point of strong over-densities in cosmological spacetimes. Specific applications include st…