Anomalous commutators for energymomentum tensors
Abstract
Anomalous contributions to the energymomentum commutators are calculated for even dimensions, by using a nonperturbative approach that combines operator product expansion and BjorkenJohnsonLow limit techniques. We first study the two dimensional case and give the covariant expression for the commutators. The expression in terms of lightcone coordinates is then calculated and found to be in perfect agreement with the results in the literature. The particular scenario of the lightcone frame is revisited using a reformulation of the BJL limit in such a frame. The arguments used for $n=2$ are then generalized to the case of any even dimensional Minkowskian spacetime and it is shown that there are no anomalous contributions to the commutators for $n\not=2$. These results are found to be valid for both fermionic and bosonic free fields. A generalization of the BJLlimit is later used to obtain double commutators of energymomentum tensors and to study the Jacobi identity. The two dimensional case is studied and we find no existance of 3cocycles in both the Abelian and nonAbelian case.
 Publication:

arXiv eprints
 Pub Date:
 May 1995
 arXiv:
 arXiv:hepth/9505010
 Bibcode:
 1995hep.th....5010M
 Keywords:

 High Energy Physics  Theory
 EPrint:
 17 pages, latex, no figures