THE POINT SPECTRUM OF UNITARY DILATIONS IN KREIN SPACES

For a bicontractive operator T on a Krein space the connections betwee n its eigenvalues and eigenstructure and the eigenvalues and eigenstru cture of its minimal unitary dilation U are studied. For eigenvalues o n the unit circle of T in general only part of the eigenspace of T wil l return as an eigenspace of U and the corresponding eigenvalue will b e a singular critical point of U.