SUSY and Dark Matter Results from ATLAS

New results from LHC are increasingly challenging the limits of the Standard Model of particle physics. Some of the most attractive scenarios for new physics are Supersymmet- ric models. In addition to solving some of the shortcomings of the Standard Model (e.g. hierarchy problem, Higgs mass corrections, gauge coupling unification) they also provide a suitable Dark Matter candidate, which could be produced at the LHC. We present the latest searches for Supersymmetry in events with high-energy final states and large missing transverse momentum for 4.7 fb−1 of proton-proton collisions at √s = 7 TeV as recorded by the ATLAS detector at the Large Hadron Collider. The data is interpreted in models where the Dark Matter candidate is dominantly produced in cascade decays of heavier unstable supersymmetric particles together with high-pT Standard Model parti- cles. We also present more model-independent searches for one single highly energetic jet or photon together with large amount of missing energy, showing the first results for a mono-jet analysis. Such signals are highly relevant for Dark Matter studies and assume that the DM candidates are pair-produced at the LHC and that all other particles are too heavy to be produced directly. So far no excess above the Standard Model background expectation is observed.