(New page: Q: Find the smallest field that has exactly 6 subfields? From our work and theorem 22.3 we know that a field of order p^n has a single subfield of order p^m for each m which divides n. So...)
 
 
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From our work and theorem 22.3 we know that a field of order p^n has a single subfield of order p^m for each m which divides n. So we must look for the smallest n with 6 divisors.  
 
From our work and theorem 22.3 we know that a field of order p^n has a single subfield of order p^m for each m which divides n. So we must look for the smallest n with 6 divisors.  
  
n    Divisors  
+
n    Divisors
 +
 
 
1    1
 
1    1
 +
 
2    1,2
 
2    1,2
 +
 
3    1,3
 
3    1,3
 +
 
4    1,2,4
 
4    1,2,4
 +
 
5    1,5  
 
5    1,5  
 +
 
6    1,2,3,6
 
6    1,2,3,6
 +
 
7    1,7
 
7    1,7
 +
 
8    1,2,4,8
 
8    1,2,4,8
 +
 
9    1,3,9
 
9    1,3,9
 +
 
10    1,2,5,10
 
10    1,2,5,10
 +
 
11    1,11
 
11    1,11
 +
 
12    1,2,3,4,6,12
 
12    1,2,3,4,6,12
 +
  
 
Eureka!
 
Eureka!

Latest revision as of 04:11, 30 November 2012

Q: Find the smallest field that has exactly 6 subfields?

From our work and theorem 22.3 we know that a field of order p^n has a single subfield of order p^m for each m which divides n. So we must look for the smallest n with 6 divisors.

n Divisors

1 1

2 1,2

3 1,3

4 1,2,4

5 1,5

6 1,2,3,6

7 1,7

8 1,2,4,8

9 1,3,9

10 1,2,5,10

11 1,11

12 1,2,3,4,6,12


Eureka!

Thus choosing the smallest prime p=2 we see that the smallest field that has exactly 6 subfields has order 2^12.

--Bakey 09:11, 30 November 2012 (UTC)

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