Four-dimensional spectrum generating algebra for superstrings
Renann Lipinski Jusinskas, Aravindhan Srinivasan · Physical review. D/Physical review. D. · 2026
We present the spectrum generating algebra for the hybrid string with manifest N = 1 super Poincaré symmetry in R 3 , 1 × R 6 . Our Del-Giudice–Di-Vecchia–Fubini operators establish a one-to-one correspondence with the conventional superstring spectrum, while making its four-dimensional structure manifest. We also discuss part of the antifield spectrum, and introduce a simple realization of the supersymmetry charges involving the R 6 directions. As an application, we algebraically compute the helicity partition function. These results provide new tools for analyzing four-dimensional on-shell superspaces and may extend naturally to phenomenologically relevant compactifications.