Is the Null Space of an Operator Defined by Its Zero Eigenvalue?

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maNoFchangE
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Suppose ##T## is an operator in a finite dimensional complex vector space and it has a zero eigenvalue. If ##v## is the corresponding eigenvector, then
$$
Tv=0v=0
$$
Does it mean then that ##\textrm{null }T## consists of all eigenvectors with the zero eigenvalue?
What if ##T## does not have zero eigenvalue? Does it mean that its null space is just the zero vector?

Thanks
 
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maNoFchangE said:
Suppose ##T## is an operator in a finite dimensional complex vector space and it has a zero eigenvalue. If ##v## is the corresponding eigenvector, then
$$
Tv=0v=0
$$
Does it mean then that ##\textrm{null }T## consists of all eigenvectors with the zero eigenvalue?
What if ##T## does not have zero eigenvalue? Does it mean that its null space is just the zero vector?

Thanks
Yes.
(Except that ##\textrm{null }T## consists of all eigenvectors with the zero eigenvalue and the 0 vector.)
 
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Samy_A said:
Yes.
So, the answer to all of my questions is affirmative?
Then, if ##T## does not have a zero eigenvalue, it's equivalent of being injective.
 
maNoFchangE said:
So, the answer to all of my questions is affirmative?
Then, if ##T## does not have a zero eigenvalue, it's equivalent of being injective.
For a linear operator, yes.
(I should have mentioned that in my first answer too, I just assumed you meant that T is a linear operator.)
 
Yes, it's linear.