Beta functions for the duality-invariant sigma model

A bstract The O ( d, d ) invariant worldsheet theory for bosonic string with abelian isometries is employed to compute the beta functions and Weyl anomaly at one-loop. We show that vanishing of coefficients implies equations motion Maharana-Schwarz action. give a self-contained introduction into required techniques, including functions, two-dimensional sigma models background field method. This sets stage sequel this paper on generalizations higher loops ? ? corrections.