Non-local charges and quantum integrability of sigma models on the symmetric spaces SO(2n)/SO(n) × SO(n) and sp(2n)/sp(n) × Sp(n)

Non-local conserved charges in two-dimensional sigma models with target spaces SO(2n)/SO(n) x SO(n) and Sp(2n)/ Sp(n) x Sp(n) are shown to survive quantization, unspoiled by anomalies; these theories are therefore integrable at the quantum level. Local, higher-spin, conserved charges are also shown to survive quantization in the SO(2n)/SO(n) x SO(n) models. (C) 2004 Published by Elsevier B.V.