Proving Entire Functions are Constant: f, e^f, Re f

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The discussion centers on proving that if an entire function \( f \) is such that \( e^f \) is bounded, then \( f \) must be constant. Additionally, it asserts that if the real part of \( f \) (Re \( f \)) is bounded, \( f \) is also constant. The key theorem referenced is Liouville's theorem, which states that any bounded entire function is constant. The participants suggest using suitable exponentials and discuss the implications of path integrals in complex analysis.

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let f be an entire function..

1) prove if e^f is bounded then f is constant
2) prove that if Re f is bounded then f is constant

i'm guessing you would have to use suitable exponentials but i don't have a good enough idea of what to do here. any help would be greatly appreciated :Dxx
 
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You can start with if an entire function is bounded everywhere, it's constant.

http://en.wikipedia.org/wiki/Liouville's_theorem_(complex_analysis)

I think the proof moves the absolute value bars into the integral a bit prematurely (as generally a path integral of a real function can give a complex number as an answer, but I can't be bothered to check if in this case it actually comes out real all the time), but the basic idea is there
 

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