Cosmology is the science of studying the Universe as a whole, its origin, its composition and its properties. We are particularly interested in investigating the cosmic microwave background, the relic radiation from the Big Bang, and in developing and deploying advanced statistical techniques to compare theory and observations, a field which is known as Astrostatistics.
We are part of CAPAC, Imperial's Centre for Astroparticle Physics and Cosmology. At Imperial Astrophysics, we are interested in the following subjects:
- Astroparticle physics: this looks at various particles as messengers from the Universe, for example dark matter, neutrinos and cosmic rays. We are developing new tools to constrain fundamental physics using astroparticle probes, including direct and indirect dark matter detection techniques.
- Cosmology and the cosmic microwave background: the relic radiation from the Big Bang is one of the pillars of modern cosmology. We are involved in the data analysis of the Planck satellite, currently observing the microwave sky.
- Dark energy: the mysterious component that is apparently driving the expansion of the Universe in an ever accelerating way. We are interested in using a variety of cosmological probes to constrain the properties of dark energy, and in helping design future measurements, from the ground and from space.
- The primordial Universe: we work towards understanding the period of ultra-fast expansion known as "inflation", which expanded the Universe exponentially over a very short amount of time right after the Big Bang.
THE COSMIC MICROWAVE BACKGROUND
The Cosmic Microwave Background, or CMB, is one of the most important confirmed predictions of the Big Bang model of our observed expanding Universe. It consists of light that last interacted with other matter in the Universe about 400,000 years after the Big Bang. The CMB therefore traces the state of the Universe at this early time, when it was hot, dense and much simpler than it is today.
Experiments like MAXIMA and BOOMERANG, both with strong Imperial involvement, first mapped the CMB on the sub-degree scales, allowing the first measurement of the global curvature of spacetime, equivalent in Einstein's General Relativity to the overall density of matter and energy. Imperial is now involved in the analysis of data and th extraction of science with ESA's Planck Surveyor satellite, which will map the intensity and polarization of the CMB over the entire sky with a higher resolution and sensitivity than has previously been achieved.
We are involved in the development of theoretical and statistical tools for the burgeoning field of astroparticle physics, one of whose aims is to provide information on the nature and properties of the dark matter particle in ways that are complementary to what can be gleaned from colliders.
For example, we are involved in predicting the signatures of dark matter in a variety of astrophysical channels, including gamma-ray emission from the centre of the Milky Way and from nearby dwarf galaxies, neutrino emissions from the centre of the Sun and of the Earth, positron signals from local dark matter clumps and recoil signals from direct detection experiments in deep underground laboratories. We have developed a new tool for the statistical analysis of supersymmetry phenomenology, called SuperBayeS.
Imperial astrophysicists are thus at the cutting edge of a worldwide effort to usher in the era of dark matter astronomy.