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QEP with Cayley Transform.
With the socalled Cayley transform,
where the parameters , , and are chosen such that
, the original QEP (9.1) becomes

(262) 
where
,
, and
.
Eigenvalues of the original QEP (9.1)
close to the antishift are
transformed into large (in modulus) eigenvalues of the QEP
(9.18). Eigenvalues close to the shift
correspond to eigenvalues of (9.17) close to .
Note that the triple
is symmetric
if that is the case for the real triple and if , ,
and are real.
Susan Blackford
20001120