On analytic normal operators
S. L. Jamison · Proceedings of the American Mathematical Society · 1954
A bounded linear transformation of an abstract Hilbert space 5C into itself will be called an operator on 3C.A one-parameter family P(e) of operators on 3C will be called regular on the interval |e| 0 as »-»oo.Therefore (1) T*(e) -P*+eP* + e2P2+--. .