@inbook{242fe2ca634d408caf2eaebd7b71311c,

title = "Algebraic Structure",

abstract = "In gauge theory, we understand matter and gauge fields by transformation under Lie algebras. We have seen that string theory naturally realizes such algebra. In heterotic string, momentum-winding quantum numbers provide representation of a state. Considering massive states and twisted states, this algebra is generalized it to the affine Lie algebra. It is generalized to twisted Lie algebra that describes twisted sector spectrum, which is a special feature in orbifold theory. Thus, it is crucial to understand the structure of the algebra.",

author = "Choi, {Kang Sin} and Kim, {Jihn E.}",

note = "Publisher Copyright: {\textcopyright} 2020, Springer Nature Switzerland AG.",

year = "2020",

doi = "10.1007/978-3-030-54005-0_12",

language = "English",

series = "Lecture Notes in Physics",

publisher = "Springer Science and Business Media Deutschland GmbH",

pages = "339--379",

booktitle = "Lecture Notes in Physics",

}