Parallel Sesion: Gravity and Cosmology
- Jessica Turner (IPPP, Durham University)
Mr William Emond (University of Nottingham)
We extend a previous self-tuning analysis of the most general scalar-tensor theory of gravity in four dimensions with second order field equations by considering a generalized coupling to the matter sector. Through allowing a disformal coupling to matter we are able to extend the Fab Four model and construct a new class of theories that are able to tune away the cosmological constant on...
Mr James Cook (King's College London)
In Khronometric theory we break Lorentz invariance by introducing a preferred time direction, and hence, equipping our spacetime manifold with a foliation of space-like surfaces. Our primary tool to solve the equations of motion is such a spacetime is Numerical General Relativity (NGR). We investigate how we can use this tool, to solve the equations of motion for a blackhole solution in...
Mr Thomas Helfer (Kings College London)
The classical equations of motion for an axion possess localized, oscillating solutions, which we refer to as "axion stars". We study, for the first time, collapse of axion stars numerically using the full Einstein equations of general relativity. We identify three states: i) long-lived oscillating axion star solutions ii) collapse to a BH and iii) complete dispersal due to gravitational...
Mr David Rodriguez Roman (King's College London)
Due to change of space-time during Inflation and Reheating, spectators field present during these epochs are going to be excited. This can be seen as a particle production. I am going to present the production of a field with no coupling to any other field, the only possible way of interaction will be through gravity. Some problems will arise due to the divergences present in this model...