Solution

ID: past-exam-of-the-short-options-paper-shared-by-prelims-and-parts-a-and-b-of-the-physics-course-of-the-university-of-oxford/2015/s7/1/5/solution

In dimensions the antisymmetric angular momentum tensor has components
There are independent rotation generators. Together with translation generators and one time-translation generator, the standard Noether charge enumeration is therefore
The word independent here counts symmetry generators and tensor components; it needs qualification if it is meant as functional independence of all charges for only two particles in arbitrarily high dimension. In centre-of-mass coordinates, . Consequently , a nontrivial identity from dimension five onwards, since . Thus the displayed number is the symmetry-charge count; it is not an assertion that these functions have unrestricted values for a two-particle realization in every .

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