ANOMALIES OF COMPLEX VARIATIONAL PHASE-SHIFTS

It is argued, contrary to various claims and expectations, that the phase shifts calculated via variational principles for the t matrix involving complex algebra may exhibit anomalous behavior. These anomalies are numerically demonstrated in the case of the complex Kohn and the Newton variational principles for the t matrix and are expected to appear for other similar variational principles for the t matrix, such as the Takatsuka-McKoy variational principle.

ANOMALIES OF VARIATIONAL PHASE-SHIFTS

It is demonstrated, contrary to various claims, that the phase shifts calculated via variational principles involving the Green function may exhibit anomalous behavior. These anomalies may appear in variational principles for the K matrix (Schwinger variational principle) of potential V, for (K-V) (Kohn-type and Newton variational principles), and other variational principles of higher order (Takatsuka-McKoy variational principle).