Abstract
This lecture describes the various candidates for exotic dark matter. First, the comparative advantages and shortcomings of the various types of dark matter are explained: cold, warm or hot, depending on whether the particles decouple from the rest of the universe while they are relativistic or not. The mass spectrum of black halos is very different in these cases, for example in the cold dark matter model, which is the standard model today, the number of small structures is very high compared with observations, one of the major problems of the model. We then describe the constraints imposed by Pauli's principle, if the particles are fermions, or Liouville's theorem in all cases, since particles are not dissipative. It turns out that the latter theorem is the strongest, and constrains dark matter particles to a mass greater than a few keV. The Standard Model and its favorite particles, the WIMPS, are discussed, as is the miracle of WIMPS, which are particles that annihilate by weak interaction, and whose relic density today falls just short of the observed value. However, the limits of direct observation of WIMPS in underground laboratories, and the non-detection of such particles at CERN's LHC, justify the investigation of other candidates. A wide range of possibilities is discussed, from sterile neutrinos (lukewarm dark matter) to extra dimensions that would give particles mass, etc.
