N = 2 supersymmetric gauge theories, branes and orientifolds Original Research Article

Starting with configurations of fourbranes, fivebranes, sixbranes and orientifolds in type 11A string theory we derive via M-theory the curves solving N = 2 supersymmetric gauge theories with gauge groups SO(N) and Sp(2N). We also obtain new curves describing theories with product gauge groups. A crucial role in the discussion is played by the interaction of the orientifolds with the NS-fivebranes.