Gravitational Effects from Amplitudes for String-Brane Interactions

PhDIn this thesis we examine both high and low energy gravitational phenomena using amplitudes derived from a quantum description of interactions between strings and branes. We demonstrate that the coupling of branes to the massless states of the closed string exactly match the couplings of these branes at low energy to the supergravity fields associated with these states. We examine the scattering of massive closed strings from a brane at high energy and large impact parameters and it is concluded that this process can be well approximated by an eikonal descriptio