... Xν∂βXµ). (3.2.44)18arXiv:hep-th/9709062 v2 30 Mar 1998CERN-TH/9 7-2 18hep-th/9709062 INTRODUCTION TO SUPERSTRING THEORY Elias Kiritsis∗ Theory Division, CERN,CH-1211, Geneva 23, SWITZERLANDAbstractIn ... Inthe quantum theory, coordinates and momenta are non-commuting operators. A specificordering prescription has to be made in order to define them as well-defined operators inthe quantum theory. In ... notes, an introduction to superstring theory is presented. Classi-cal strings, covariant and light-cone quantization, supersymmetric strings, anomalycancelation, compactification, T-duality,...