Searches for new Physics in multileptons or like-sign leptons with the ATLAS detector

Events containing several leptons or two like-sign leptons are rarely produced in the Standard Model (SM), but occur with an enhanced rate in many models of new physics. We look for anomalous production of pairs of prompt like sign leptons or events with three or more leptons using the full data sample recorded in 2011 at sqrt(s) =7 TeV centre-of-mass energy by the ATLAS experiment at the LHC