Searches for Dark Matter with the ATLAS experiment

ATLAS is a multi-purpose detector aimed at fully exploiting the discovery potential of the proton-proton collisions at a center of mass energy of 8-14 TeV provided by CERN Large Hadron Collider. It is able to precisely identify and measure the properties of electrons, muons, photons, taus and hadronic jets. Thanks to an excellent hermeticity it is able to infer the production of neutrinos and dark matter particles from conservation of momentum using the missing energy observable. This talk will focus on the results of several dedicated searches for WIMP Dark Matter using the ATLAS detector. Among these searches are the so called "Mono-X" searches looking for signatures with large missing momentum recoiling against a gauge boson. We also present searches for decays of the Higgs boson into invisible states and searches for final states with missing transverse energy and third generation quarks. The results are interpreted in terms of Effective Field Theories as well as Simplified Models, and limits on nucleon-WIMP cross sections are inferred for both spin-dependent and spin-independent scenarios. Finally some prospects for the upcoming LHC Run 2 with collisions at the unprecedented 13-14 TeV center-of-mass energies will be presented.