Research Activities
Current members of the group include academics Peter Coles, Stephen Fairhurst, Leonid Grishchuk, Bangalore Sathyaprakash, Bernard Schutz (part time), and Patrick Sutton, six postdoctoral fellows and seven PhD students. The Group co-founded the British-German GEO600, is a member of the LIGO Scientific Collaboration, and involved in the space-based LISA and the design study of the 3rd generation Einstein gravitational-wave Telescope . The research interests of the group include quantum processes in the early Universe, cosmic microwave and gravitational wave backgrounds, modeling binary black hole orbits and their gravitational wave emission, strong field tests of gravity, and the development of algorithms and software to search for binary inspirals, transient bursts, and stochastic backgrounds. The group's data analysis is focussed on searching for signals from transient sources, binary neutron stars and black holes, and stochastic gravitational waves. Cardiff is one of GEO's data archival centres and hosts also the strain channel from the LIGO detectors on its spinning storage media. The data is analyzed using large computer clusters consisting of a total of 360 processors, as well as access to the Cardiff University central Advanced Research Computing @ Cardiff (ARCCA) cluster of 2048 processors.
Tutorial
For a non-technical introduction to gravitational physics and gravitational waves, we have produced a tutorial.
Gravitational Wave Sources
Likely sources of detectable gravitational radiation roughly fall into four categories: the inspiral and coalescence of compact binary objects (black holes and/or neutron stars), burst sources such as supernovae and gamma ray bursts, isolated neutron stars and other sources of continuous waves, and stochastic backgrounds. At Cardiff, research related to sources focuses on compact binary inspiral, isolated neutron stars, and backgrounds of relic gravitons.
More about Gravitational Wave Sources
Gravitational Wave Searches
One of the main research topic of our group is the direct detection of gravitational waves, which can be achieved by the development of signal analysis methods. Although we focus our efforts on analysing the output of ground-based detectors such as LIGO/VIRGO/GEO600, nevertheless we are also developing algorithms and tools to analyse the data from future detectors such as advanced LIGO (ground-based) and LISA (space-craft). Concerning the potential sources of gravitational waves that ground-based detectors can detect, we are particularly interested with the search of:
- Inspiral and coalescence of compact binary objects such as neutron stars and/or black holes
- Burst sources such as the collapse of massive stars in supernova explosions, or gravitational-wave emitted in coincidence with gamma-ray bursts
- Stochastic background, which is expected to arise as a superposition of large number of unresolved sources, from different directions in the sky, and different polarizations.
More details about Gravitational Wave Searches
Early Universe Cosmology
The origin of the Universe is the central problem of cosmology. We expect to shed light on this problem by measuring relic gravitational waves. The existence of relic gravitational waves is a consequence of superadiabatic (parametric) amplification of the waves' zero-point quantum oscillations by the strong variable gravitational field of the very early Universe. The current research of the Gravitational Physics group is focused on refining the theory of relic gravitational waves.
More details on cosmology research
Black Holes
A proper understanding of the nature of black holes is important from both a fundamental and phenomonological point of view. Researchers at Cardiff are involved in understanding local formulations of black holes, in terms of isolated and dynamical horizons, rather than the "teleological" event horizon.