Copernicus Complexio (COCO)


Copernicus and his “Complexio”

For as long as humans have engaged in scientific thought, one question that has always been raised is: “Do we live in a special place in the universe?”. The paradigm shifting claim by Nicolaus Copernicus was that the Sun and the Earth are not really special at all — we are not privileged observers in any sense.

Surprisingly, however, modern astronomy often points in a different direction — observations of the Milky Way and its satellite galaxies seem to often disagree with the predictions of the standard cosmological model. Even now, there seems to be a dilemma (or “complexio”) surrounding this question.

The Copernicus Complexio (or COCO) simulations aim to replicate the observed universe with over 13 billion particles in a supercomputer to gain insight into one of the most fundamental questions in science: “Is the Milky Way unique? And if so, why?”

The simulations were run as part of the Virgo consortium in conjunction with the ICM at the University of Warsaw.

Warm dark matter

Cold dark matter (CDM) has long been the standard dark matter candidate, and has done an excellent job in matching real observations of the universe.

However, particle physicists tell us that there could be a different kind of particle, known as a sterile neutrino, which would constitute warm dark matter (WDM), in which the particles move much faster in the early universe.

The two models make different predictions for the nature of structure formation in the universe, with fewer low-mass haloes (the gravitational sinks in which galaxies form) being created in WDM. COCO simulates WDM and CDM cosmologies to test the differences between the two.