The orbifolds of permutation-type as physical string systems at multiples of [formula omitted]: III. The spectra of [formula omitted] strings

Abstract

In the second paper of this series, I obtained the twisted BRST systems and extended physical-state conditions of all twisted open and closed c ˆ = 52 strings. In this paper, I supplement the extended physical-state conditions with the explicit form of the extended (twisted) Virasoro generators of all c ˆ = 52 strings, which allows us to discuss the physical spectra of these systems. Surprisingly, all the c ˆ = 52 spectra admit an equivalent description in terms of generically-unconventional Virasoro generators at c = 26 . This description strongly supports our prior conjecture that the c ˆ = 52 strings are free of negative-norm states, and moreover shows that the spectra of some of the simpler cases are equivalent to those of ordinary untwisted open and closed c = 26 strings.