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Research Fellows Directory

Constantinos Skordis

Dr Constantinos Skordis

Research Fellow


University of Nottingham

Research summary

I work in the field of cosmology, which studies the expansion of Universe on the largest scales and its effect on the formation of structures, such as galaxies. The study of the cosmic expansion requires full knowledge of the constituents of matter that fill the universe, as well as, the theory of gravity. Our best candidate theory of gravity to date is Einstein's general relativity while all known forms of stable matter are either radiation (photons and neutrinos), or baryons (protons and other nuclei). However, when confronted with observations this paradigm fails in two important respects.

The observed dynamics of galaxies leads us to posit a missing component of matter invisible to photons, which goes by the name of Dark Matter (DM). This simple and attractive amendment is highly successful in explaining the dynamics of our universe, but the agreement with observations is not without tension. Even when augmented with DM, the aforementioned paradigm fails in a profound way. It predicts that the expansion of the universe must be slowing down while on the contrary it has been observed that it is actually speeding up! This requires a second missing component called the dark energy (DE). Unlike CDM, for which many compelling proposals exist, the nature of dark energy is a complete mystery and one of the greatest puzzles of modern physics. It may thus be possible that the inference of CDM and DE based on general relativity is incorrect.

My research focuses on critically questioning the nature of DM and DE. I am tackling the problem from two angles. From the phenomenological side, I am developing a framework to distinguish possible departures from general relativity from the effects that can only be attributed to dark matter or dark energy. From the theoretical side, I'm investigating a number of gravitational theories that aim to explain both DM and DE.

Demystifying the nature of Dark Matter and Dark Energy will most certainly change our view of the cosmos.

Interests and expertise (Subject groups)

Grants awarded

Testing gravity on cosmological scales

Scheme: University Research Fellowship

Dates: Oct 2010 - Nov 2014

Value: £489,373.46