论文标题
旧二元性和新异常
Old Dualities and New Anomalies
论文作者
论文摘要
我们回顾一个问题,弦的世界表理论是否承认全球O(d,d)对称性。我们考虑了目标空间理论的截断,其中磁场独立于d坐标,即o(d,d,r)不变。除非将绕组和质量中心动量截断为零,否则世界表理论不是O(d,d,r)不变的。我们证明了这种截断的一致性,并给出了明显的O(d,d,r)不变动作,通过包括所有外部和内部目标空间场来概括了由于Tseytlin引起的公式。结果表明,由于手性玻色子,这种对称性是异常的。使用外部B场的绿色 - 奇瓦兹机制取消了异常。
We revisit the question whether the worldsheet theory of a string admits a global O(d,d) symmetry. We consider the truncation of the target space theory in which fields are independent of d coordinates, which is O(d,d,R) invariant. The worldsheet theory is not O(d,d,R) invariant, unless it is truncated by setting winding and center-of-mass momenta to zero. We prove consistency of this truncation and give a manifestly O(d,d,R) invariant action, generalizing a formulation due to Tseytlin by including all external and internal target space fields. It is shown that, due to chiral bosons, this symmetry is anomalous. The anomaly is cancelled by a Green-Schwarz mechanism that utilizes the external B-field.