Closed string degeneracies | A First Course in String Theory
(a) State the values of and give the degeneracies for the first five mass levels of the closed bosonic string theory.
p.288 Equation (13.48):
p.290 “A basis vector belongs to the state space _if and only if_ it satisfies the level-matching constraint”
Assuming the signs of the wave functions do not matter:
p.291 How come the number of the components of the matrix represents the number of states?
p.292 For massless states, we have only one and , where and cannot interchange. So and also cannot interchange. In other words, in Equation (13.69), there is no double count. All the states are independent.
But for non-massless states, this probably is not true anymore:
— Me@2018-04-17 04:47:31 PM
2018.04.17 Tuesday (c) All rights reserved by ACHK