Adjoining Elements to Finite Fields: Finding Generators

In summary, the conversation discusses the field F_5 and adjoining a square root of 2 (2^{1/4}). The problem is finding a generator for the cyclic group inside F_5(2^{1/4}) and generalizing from the F_5(2^{1/2}) case. It is suggested to notate the ring as \mathbb{F}_5[X]/(X^4-2) and it is noted that finding a generator for the cyclic group is a difficult problem that may require testing all elements. The fact that \mathbb{F}_5 is cyclic does not provide a solution.
  • #1
R.P.F.
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Homework Statement



I have the field [tex] F_5 [/tex] and I adjoin some square root of 2 , say [tex]2^{1/4}[/tex]. Is there a way to see that the multiplicative group inside [tex]F_5(2^{1/4})[/tex] is cyclic and find the generator?

Homework Equations


The Attempt at a Solution



I did the [tex]F_5(2^{1/2})[/tex] case and think the generator is [tex]2+\sqrt{2}[/tex]. But don't know how this generalizes..
Thanks!
 
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  • #2
I don't really like the exponent notation. You should write your ring as [itex]\mathbb{F}_5[X]/(X^4-2)[/itex].

Finding a generator for the cyclic group is a quite difficult problem and still an active problem of research. I fear that the only solution is to test all the elements and see whether they are cyclic.
 
  • #3
micromass said:
I don't really like the exponent notation. You should write your ring as [itex]\mathbb{F}_5[X]/(X^4-2)[/itex].

Finding a generator for the cyclic group is a quite difficult problem and still an active problem of research. I fear that the only solution is to test all the elements and see whether they are cyclic.

Really?:cry::cry: Even the fact that [tex]\mathbb{F}_5[/tex] itself is cyclic does not help..?
 

FAQ: Adjoining Elements to Finite Fields: Finding Generators

What is an adjoining element to a field?

An adjoining element to a field is an element that can be added to a field in order to extend the field and create a larger field. It is typically used in algebraic number theory and algebraic geometry to study properties of fields.

How is an adjoining element to a field represented?

An adjoining element to a field is typically represented by a polynomial with coefficients in the field. The adjoining element is then the root of this polynomial that is added to the field. For example, the adjoining element to the field of rational numbers represented by the polynomial x^2 - 2 would be the square root of 2.

What is the significance of adjoining elements to fields?

Adjoining elements to fields allows for the creation of larger fields that can be used to study more complex mathematical objects. It also allows for the study of algebraic extensions, which are important in many areas of mathematics.

Can any element be adjoined to a field?

No, not every element can be adjoined to a field. The element must satisfy certain conditions, such as being algebraic over the field, in order to be adjoined. Additionally, the field must also be closed under the operations of addition, subtraction, multiplication, and division with the adjoining element.

How are adjoining elements to fields used in mathematical proofs?

Adjoining elements to fields can be used in mathematical proofs to show the existence of certain mathematical objects or to prove theorems about them. They can also be used to construct fields with desired properties, such as being algebraically closed or having a certain degree of extension.

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