(a) Under parity, a true scalar operator does not change: whereas a pseudoscalar changes sign. Show therefore that [,f] = 0 for a true scalar,

(a) Under parity, a “true” scalar operator does not change:

whereas a pseudoscalar changes sign. Show therefore that [П̂,f̂] = 0 for a “true” scalar, whereas [П̂,f̂] = 0 for a pseudoscalar.

(b) Similarly, a “true” vector changes sign

whereas a pseudovector is unchanged. Show therefore that [П̂,V̂] = 0 for a “true” vector and [П̂,V̂] = 0 for a pseudovector.

= f.