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daniel_i_l
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Homework Statement
V is a unitarian space of finite dimensions and T:V->V is a linear transformation.
Every eigenvector of T is an eigenvector of T* (where (Tv,u) = (v,T*u) for all u and v in V).
Prove that T(T*) = (T*)T.
Homework Equations
The Attempt at a Solution
First of all, since the space in unitarian both T and T* can be expressed as a jordan matrix. It's easy to show that if J is the jordan matrix of T then [tex]\bar{J}[/tex] is the jordan matrix of T*. My idea is that since every eigenvector of T is an eigenvector of T* then there exists some base of V where T is expressed as J and T* is expressed as [tex]\bar{J}[/tex]. If that where true than it would be easy to answer the question
(Since then there would be a matrix M to that [tex] [T] = M^{-1}JM [/tex] ,
[tex][T^{*}] = M^{-1} \bar{J} M [/tex] and then
[tex] [T^{*}][T] = M^{-1} \bar{J} M M^{-1} J M = M^{-1} \bar{J} J M =
J M^{-1} \bar{J} M = [T][T^{*}] [/tex]
but I can't prove that such a base exists. In all the examples I've tried there's a base like that.
Is this the right direction? If so, how do I prove that a base exists?
Is there a better way to approach the problem?
Thanks.