8 papers
Locating critical solutions in numerical relativity using automatic differentiation
David Bambague, Miguel Bezares, Katy Clough +1
Numerical relativity is a term used to describe the solution of the full non-linear Einstein Equations as an initial value problem using numerical methods. Individual simulations a…
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…
Black hole binaries in shift-symmetric Einstein-scalar-Gauss-Bonnet gravity
Maxence Corman, Llibert Aresté Saló, Katy Clough
In shift-symmetric Einstein-scalar-Gauss-Bonnet gravity, stationary black holes have a non-vanishing scalar charge. During the inspiral, the phase evolution is modified by several…
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…
Challenges in the nonlinear evolution of unequal mass binaries in sGB gravity
Llibert Aresté Saló, Daniela D. Doneva, Katy Clough +2
It has only recently become possible to simulate the full nonlinear dynamics of binary black holes in scalar-Gauss-Bonnet theories of gravity. The simulations remain technically ch…
Inflaton Dynamics in Higher-Derivative Scalar-Tensor Theories of Gravity
Sam E. Brady, Katy Clough, Pau Figueras +1
During inflation, higher derivative terms in the gravitational action may play a significant role. Building on new stable formulations of four-derivative scalar-tensor theories, we…
New Horizons for Psi: Studying fundamental fields with numerical relativity
Katy Clough
This set of notes was designed to accompany two hours of lectures and practical exercises at the New Horizons for Psi workshop in Lisbon in July 2024 entitled "Studying fundamental…