Find Entire Functions with |f(z)|=1 for all |z|=1: Proving Vigorously

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Discussion Overview

The discussion revolves around finding entire functions \( f \) such that \( |f(z)| = 1 \) for all \( |z| = 1 \). Participants are seeking rigorous proofs related to this problem, exploring the implications of the minimum modulus theorem.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • Some participants suggest that by the minimum modulus theorem, such a function must be constant.
  • One participant questions whether the function \( f(z) = z \) could be considered a constant function in this context.
  • A later reply acknowledges a misunderstanding regarding the original problem's conditions.

Areas of Agreement / Disagreement

Participants do not reach a consensus, as there is confusion about the implications of the minimum modulus theorem and the nature of the function \( f(z) \).

Contextual Notes

There is a potential misunderstanding regarding the application of the minimum modulus theorem and its implications for the nature of entire functions under the specified conditions.

iamqsqsqs
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Difficult with this problem.
Find all entire functions f such that |f(z)| = 1 for all z with |z| = 1.

Are there any vigorous proofs?
 
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iamqsqsqs said:
Difficult with this problem.
Find all entire functions f such that |f(z)| = 1 for all z with |z| = 1.

Are there any vigorous proofs?



By the minimum modulus theorem, such a function must be constant...

DonAntonio
 
DonAntonio said:
By the minimum modulus theorem, such a function must be constant...

DonAntonio

So the function f(z)=z is a constant then??
 
micromass said:
So the function f(z)=z is a constant then??



Oops! I missed the "for all |z| = 1" in the OP...

DonAntonio
 

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