Paper detail

Heterotic wrapping rules

We show that the same wrapping rules that have been derived for the branes of IIA and IIB string theory also apply to the branes of the toroidally compactified heterotic string theory. Moreover, we show that applying these wrapping rules to the IIA theory compactified over K3 is consistent with the well-known duality between the heterotic string theory compactified over T^4 and the IIA string theory compactified over K3. We derive a simple rule that relates, in any dimension, the T-duality representation of the branes of the toroidally compactified heterotic theory to the relevant R-symmetry representation of the central charges in the supersymmetry algebra. We show that, in the general case, the degeneracy of the BPS conditions of the heterotic branes is twice as large as that of the branes of IIA and IIB string theory.