Are Algebraic Extensions Always Finite?

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Homework Help Overview

The discussion revolves around algebraic extensions and their properties, specifically addressing true or false statements regarding algebraic extensions, algebraically closed fields, and the relationship between various fields and their extensions.

Discussion Character

  • Conceptual clarification, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants explore the definitions and properties of algebraic extensions, questioning whether every algebraic extension is finite and discussing the implications of algebraically closed fields.
  • Some participants express confusion over notation and terminology, particularly regarding the distinction between rational functions and polynomial rings.
  • There is a discussion about the existence of counterexamples, particularly in relation to the algebraic closure of the rationals and the infinite nature of prime numbers.
  • Participants raise questions about specific examples and the implications of certain theorems related to algebraic independence and finite extensions.

Discussion Status

The discussion is active, with participants providing insights and raising questions. Some guidance has been offered regarding the definitions and properties of fields, but there is no explicit consensus on the true or false nature of the original statements. Multiple interpretations and lines of reasoning are being explored.

Contextual Notes

Participants note the complexity of the problems and express concern that they may require advanced mathematics. There is also mention of specific constraints related to the definitions of algebraic closure and the characteristics of fields.

  • #31
Hurkyl said:
How? Can you come up with an example?

The dot notation is definitely not always compatible with field notation, as I will show. Consider the field Z/3Z. Writing 5*2 is absurd because 5 is not an element of the field Z/3Z. You need to write 5 \cdot 2 if you want to represent the sum 2+2+2+2+2.

morphism, if you are saying that if F is a field that contains f, then n \cdot f = nf WHEN the characteristic of F is greater than n or equal to 0, then I think that is true.
 
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  • #32
ehrenfest said:
Writing 5*2 is absurd because 5 is not an element of the field Z/3Z.[/itex]
Er, yes it is. 5 denotes the same element that 2 does.
 
  • #33
OK. This is getting really technical. I would rather move on.
 

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