2019/03/01 by Schnabl, M., Vosmera, J.
#FOS: Physical sciences #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.1903.00487
We present exact expressions for elementary boundary states which describe D-branes preserving 16 or fewer supercharges in type II superstring compactified on certain self-dual 4-tori. While being manifestly superconformal, our boundary states are not a priori required to satisfy the usual free-field gluing conditions along the internal directions of the 4-tori. Our calculations proceed along the lines of Gepner's construction by recasting the N=(2,2) worldsheet sigma model on the 4-tori in terms of N=2 minimal models. Imposing general permutation gluing conditions on the N=(2,2) generators is shown to yield various stable and unstable D-branes, where the stable ones include the known 1/2-BPS and 1/4-BPS bound states of Dp-branes, as well as new non-BPS D-branes, which do not carry RR charges.