Duality Orbits, Dyon Spectrum and Gauge Theory Limit of Heterotic String Theory on T^6

Understand

For heterotic string theory compactified on T^6, we derive the complete set of T-duality invariants which characterize a pair of charge vectors (Q,P) labelling the electric and magnetic charges of the dyon.

• Using this we can identify the complete set of dyons to which the previously derived degeneracy formula can be extended.
• By going near special points in the moduli space of the theory we derive the spectrum of quarter BPS dyons in N=4 supersymmetric gauge theory with simply laced gauge groups.
• The results are in agreement with those derived from field theory analysis.