Can Any Linear Operator Be Expressed Using Hermitian Components?

andre220
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Homework Statement


Show that any linear operator \hat{L} can be written as \hat{L} = \hat{A} + i\hat{B}, where \hat{A} and \hat{B} are Hermitian operators.


Homework Equations


The properties of hermitian operators.


The Attempt at a Solution


I am not sure where to start with this one. For example, we know that if an operator, A is hermitian, then \langle g\mid A f \rangle = \langle f\mid A g\rangle^*. But I do not see how to break up L into any combination of other operators. Any help would be appreciated, perhaps a nudge in the right direction.
 
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andre220 said:
Show that any linear operator \hat{L} can be written as \hat{L} = \hat{A} + i\hat{B}, where \hat{A} and \hat{B} are Hermitian operators.
What would ##\hat L^\dagger## look like?
 
If ##\hat{A},\hat{B}## are Hermitian then ##i\hat{B}## is anti-Hermitian. So the problem is really just asking you to prove that any operator is a sum of a Hermitian part and an anti-Hermitian part. This is very similar that any real linear operator is a sum of a symmetric part and an anti-symmetric part. Do you know how that property is proved?
 
To solve this, I first used the units to work out that a= m* a/m, i.e. t=z/λ. This would allow you to determine the time duration within an interval section by section and then add this to the previous ones to obtain the age of the respective layer. However, this would require a constant thickness per year for each interval. However, since this is most likely not the case, my next consideration was that the age must be the integral of a 1/λ(z) function, which I cannot model.
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