κ-symmetry and Bogomolʹny bound Original Research Article

By applying the twistor-like transform to the GS superstring theory we fix the local fermionic gauge symmetry, known as κ-symmetry. Fixing the κ-symmetry in the GS superstring theory and the N = 1 world-sheet supersymmetry in the NSR theory proves the relation between these theories, conjectured earlier; the GS fermionic variable θ is shown to be related to the NSR worldsheet fermionic variable ψ through the twistor field Λ. Upon fixing the κ-symmetry we derive the gauge-fixed expressions for the supercharges (corresponding to spinor representations of SO(8)) and analyze the gauge-fixed space-time superalgebra. The analysis relates the κ-invariance to the Bogomol’ny-type condition, with the former appearing as a space-time superpartner of the latter. The BPS saturation appears to be crucial for the non-perturbative formulation of the κ-symmetry. The relation to the RR charges of p-brane solutions of the D = 10 supergravity is discussed.