Is the universe tied up with cosmic string?
Identifying lines of pure mass-energy across the universe.
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Mark Hindmarsh
Reader in Physics
The particle cosmology research effort at Sussex unites the Astronomy and Theoretical Particle Physics research groups.
This year our most high-profile research, in collaboration with colleagues from Imperial College London, has been our work to quantify and test the idea that there may be lines of pure mass-energy stretching across the entire universe, called cosmic strings.
Sussex has a world-leading reputation in the cross-disciplinary area of particle cosmology, a subject that emerged in the 1980s from the realisation that particle physics (the study of the constituents of matter) and cosmology (the study of the universe) on the largest scales, blend into one in the very first moments of the Big Bang.
Cosmic strings are predicted by theories of high-energy physics including superstring theory, which is based on the idea that particles are not just little points, but tiny vibrating bits of string. Cosmic strings have extraordinary amounts of mass – perhaps as much as the mass of a mountain range – packed into each metre of a tube whose width is less than a trillionth of a trillionth the size of an atom.
Sussex is a founder member of COSMOS, the UK’s world–leading cosmology supercomputing consortium fronted by Stephen Hawking. The Sussex team uncovered hints of strings in the data from NASA’s Wilkinson Microwave Anisotropy Probe, which maps the cosmic microwave background – relic radio waves from the Big Bang that fill the universe. It turned out that the best explanation for the pattern of the maps was a theory including strings.
We cannot yet see these strings directly. They are many billions of light years away, so we can only look for indirect evidence of their existence through precision measurements of the cosmic microwave background, and other cosmological signals. Key to this research was access to new Science Research Investment Fund-supported high performance computing resources at Sussex, which will become increasingly important.
The future for particle physics and cosmology at Sussex is bright. The launch of the European Space Agency’s Planck Surveyor Satellite mission in October this year will lead to a flood of new high-precision data, and a huge amount of simulation and data processing will be required to test conclusively the cosmic string scenario, as well as other theories of the very early universe.
At about the same time, the Large Hadron Collider will start colliding protons at unprecedented energies, allowing us a better understanding of the building blocks of matter and of the origin of our universe. Sussex expects to play a leading role in the world-wide effort to link together new data from cosmology and particle physics and to peel back the next layer of the cosmic onion.
