... properties that remain invariant under similarity transformations. One such 254 CONTINUOUS GROUPS AND REPRESENTATIONS Y’ Fig. 11.6 (z,y,z) and the (z‘,y’,z‘) coordinates we obtain (Fig. 11.6) ... spherical harmonics &(O, 4). LORENTZ GROUP AND ITS LIE ALGEBRA 241 and These give us the remaining generators as and (11 .138 ) (11 .139 ) (11.140) Oi satisfy the commutation relation ... 240 CONTINUOUS GROUPS AND REPRESENTATIONS induces the following change in a function f(v1, ~2): - f(V) = f Mff, P, Y)VI' (1 1.126) Taking the active view we define an operator...