Using the AdS/CFT correspondence to study phases of gauge theories, at strong coupling at finite temperature and density.

The AdS/CFT correspondence give a new perspective both at strong coupling physics of quantum field theory and the nature of the gravitational interaction. This thesis will deal with analysing the physics of gauge theories at finite temperature and density, their phase diagrams and their consequences for the physics of neutron stars, strange stars,  black holes,  cosmological fluids and strange metals.