Low Ian, Manohar Aneesh V
Jefferson Physical Laboratory, Harvard University, Cambridge, Massachusetts 02138, USA.
Phys Rev Lett. 2002 Mar 11;88(10):101602. doi: 10.1103/PhysRevLett.88.101602. Epub 2002 Feb 25.
Goldstone's theorem states that there is a massless mode for each broken symmetry generator. It has been known for a long time that the naive generalization of this counting fails to give the correct number of massless modes for spontaneously broken spacetime symmetries. We explain how to get the right count of massless modes in the general case, and discuss examples involving spontaneously broken Poincaré and conformal invariance.
戈德斯通定理指出，对于每一个破缺的对称生成元都存在一个无质量模式。长期以来人们都知道，这种计数的简单推广无法给出自发破缺时空对称性时无质量模式的正确数量。我们解释了在一般情况下如何正确计算无质量模式的数量，并讨论了涉及自发破缺庞加莱对称性和共形不变性的例子。
