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rg209
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Joined: February 5th, 2010, 9:49 am

Characteristic Function

May 4th, 2010, 7:15 pm

Could you please help me with the following problem. If E(exp(i*u*X)) = E(exp(i*u*X)/ G) where G is a sigma algebra and X a random variable then X is independent of G. In the case of two random variables it can be done using inverse Fourier transforms. Is it possible to adapt that method ?Thanks in advance.
 
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Hansi
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Joined: January 25th, 2010, 11:47 am

Characteristic Function

May 4th, 2010, 11:00 pm

Where do you run into problems?
 
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rg209
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Characteristic Function

May 5th, 2010, 2:59 pm

Not every sigma algebra is generated by a sequence of random variables or am I wrong about this.
 
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rg209
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Characteristic Function

May 9th, 2010, 12:06 am

We solved it. We had to use the fact that if the Fourier Transform is zero then the function is zero a.s. .