Triangularizability of Operators with Increasing Spectrum
نویسندگان
چکیده
We establish finiteand infinite-dimensional versions of the following assertion. If M is a matrix with the property that whenever P and Q are diagonal projections with P ≤ Q, the spectrum of PMP (considered as an operator on the range of P ) is contained in that of QMQ (considered as an operator on the range of Q), then there is a permutation matrix U such that U−1MU is triangular.
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