Anomaly cancellations in supersymmetric D = 10 gauge theory and superstring theory

Supersymmetric ten-dimensional Yang-Mills theory coupled to N=1, D=10 supergravity has gauge and gravitational anomalies that can be partially cancelled by the addition of suitable local interactions. The remaining pieces of all the anomalies cancel if the gauge group is SO(32) or E8xE8. These cancellations are automatically incorporated in the type I superstring theory based on SO(32). A superstring theory for E8xE8 has not yet been constructed. (orig.)