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Research Fellows Directory

Christian Byrnes

Dr Christian Byrnes

Research Fellow


University of Sussex

Research summary

Amazing progress has been made in the study of the universe over the last decade, leading to a “golden age of cosmology”. Progress has mainly come from experimental advances. In particular observations of the cosmic microwave background (CMB), photons which have been moving freely for most of the age of the universe, have been revolutionised by satellite observations. The pattern of tiny temperature perturbations of CMB photons contain hidden signatures of the Big Bang which are now being revealed. The same perturbations have led to the formation of all structure including galaxies, stars, even ourselves! Recently the BICEP experiment hit the headlines when it wrongly claimed to have detected gravitational waves from the big bag, the Planck satellite also made headlines later when it corrected their claims and realised a lot of high precision new data, which constitutes our best ever view onto the big bang.

The initial source of the CMB perturbations is uncertain. Inflation solves several cosmological problems, such as why the universe looks almost the same in every direction. Quantum fluctuations are inflated and may become the initial seeds of all perturbations. So inflation links the very smallest (quantum) and largest (galactic) scales.

Since inflation occurred soon after the Big Bang at higher energy scales than terrestrial experiments can ever reach, we do not know its properties. Fundamental questions remain; what caused inflation, what was the physics of this high energy process?

The CMB contains lots of information, so we need to know which signatures to look for, it is not possible to search for every conceivable pattern. My research involves accurately calculating the expected signatures from classes of inflationary models. I am also leading research into tests of the very small scale universe which we probe through primordial black holes and which cannot be probed through standard techniques. This helps to shine light on the big bang.

Interests and expertise (Subject groups)

Grants awarded

Reaching a qualitatively new understanding of the post-Planck universe

Scheme: University Research Fellowship

Dates: Jan 2017 - Dec 2019

Value: £296,647.95

Understanding the early universe - preparing theory to meet new observations

Scheme: University Research Fellowship

Dates: Oct 2012 - Dec 2016

Value: £461,514.59