Interactions Between D-branes

We focus mainly on computing the brane interactions in various scenarios andanalyzing the associated properties and dynamics.We calculated explicitly the interaction amplitudes between two parallel sets ofDp-branes with each carrying an arbitary -ux. We discussed various instabilities in-cluding the tachyonic one when the brane separation reaches string scale. We alsocomputed the open string pair production rate when there is an electric -ux present justlike Schwinger pair production in QED. However, we discovered an unexpected signif-icant enhancement of this rate when there is in addition a magnetic -ux present alongcertain directions on the other set of branes.We also analyzed the force structure for interactions between D_p-2 and Dp andfound out that the force can even be repulsive under certain conditions. We also foundout that a ND-directional electric -ux does not give rise to the open string pair pro-duction. For the present system, an exponential enhancement of the open string pairproduction rate can occur even in the absence of a magnetic -ux.