出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：In this talk, we show how the monodromy matrix, cM, can be constructed for
the two dimensional tree level string e
ective action. The pole structure of cM is derived
using its factorizability property. It is shown that the monodromy matrix transforms
non-trivially under the non-compact T-duality group, which leaves the e
ective action
invariant and this can be used to construct the monodromy matrix for more complicated
backgrounds starting from simpler ones. We construct, explicitly, cM for the exactly
solvable Nappi-Witten model, both when B = 0 and B 6= 0, where these ideas can be
directly checked.
