Counting states in heterotic SO(32) string theory  A First Course in String Theory
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Paraphrasing the description of heterotic (closed) string theory:
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 rightmoving part an open superstring theory
 sector:
 sector:
 “The standard GSO projection down to NS+ and R applies.”
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 leftmoving part a peculiar bosonic openstring theory
 There are totally 24 transverse coordinates
 8 bosonic coordinates with oscillators

16 peculiar bosonic coordinates
 can be replaced by 32 twodimensional leftmoving fermion fields,
 (anticommuting) fermion fields has and sectors

: oscillators act on the vacuum
given defines the left sector

: oscillators act on ground states
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 There are totally 24 transverse coordinates
— Me@20180920 09:51:17 PM
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