BPS BOUND STATES OF D6-BRANES AND LOWER-DIMENSIONAL D-BRANES

We construct 1/8, 1/4, and 1/2 BPS solutions spanned by diagonal elements of U(N) constant fluxes in the (6+1)-dimensional U(N) super Yang–Mills theory on T6 with topological stability. These solutions represent BPS bound states of D0, D2, D4, and D6 branes. The consistency with the D-brane charge conservation implies that unstable D0–D2–D6-brane systems in a B field decay to the BPS solutions, in which lower-dimensional D-branes are dissolved in D6-branes.