2＋1维CP^1模型拓扑项可移性研究

R emovability of the Topological Term in the 2+1 Dimensional CP￣1 Model

求得了移去２＋１维ＣＰ１模型拓扑项的经典正则变换及相应的量子么正变换，并指出模型中拓扑项的存在性不仅与微观自旋模型有关，还与系统真空态的性质有关．

The removability of the topological term in 2+1 Dimensional CP￣1 model is studied. Both the classical canonical transformation and quantum unitary transformation for the removal of the topological term are obtained. It is pointed out that,in order to give an answer to the question of whether the topological term exists or not, one has to study not only the corresponding microscopic spin model but also the vacuum structure of the CP￣1 model.