This paper considers classical strings propagating in γ-deformed AdS 3 ×S 3 backgrounds generated by certain shift T-dualities accompanied (TsT) transformations on S 3 and AdS 3 , respectively. It finds that the U(1) currents of strings with the twisted boundary conditions are equal to those in γ-deformed backgrounds generated by TsT transformations on both S 3 and AdS 3 . Applying the TsT transformations, it derives the local Lax connections and the monodromy matrices in γ-deformed backgrounds with the spectral parameter which ensure the classical integrability of the string theories.
We study the relation between the symmetry group of a Feynman diagram and its reduced diagrams.We then prove that the counterterms in the BPHZ renormalization scheme are consistent with adding counterterms to the interaction Hamiltonian in all cases,including that of Feynman diagrams with symmetry factors.
