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| -rw-r--r-- | README.md | 23 |
1 files changed, 13 insertions, 10 deletions
| @@ -4,21 +4,22 @@ the rational numbers. In order to use the functions KummerDegree and | |||
| 4 | TotalKummerFailure (described below), simply download the file | 4 | TotalKummerFailure (described below), simply download the file |
| 5 | kummer_degree.sage and include it in your SageMath session/project, | 5 | kummer_degree.sage and include it in your SageMath session/project, |
| 6 | for example with | 6 | for example with |
| 7 | |||
| 7 | ``` | 8 | ``` |
| 8 | attach(\"kummer_degree.sage\") | 9 | attach("kummer_degree.sage") |
| 9 | ``` | 10 | ``` |
| 10 | 11 | ||
| 11 | A Kummer Extension of Q is a field extension of the form Q_{M,N}:= | 12 | A Kummer Extension of Q is a field extension of the form Q{M,N}:= |
| 12 | Q(\zeta_M,G^{1/N}), where: | 13 | Q(z,G^1/N ), where: |
| 13 | 14 | ||
| 14 | * M and N are integers with N dividing M; | 15 | * M and N are integers with N dividing M; |
| 15 | * \zeta_M is a root of unity of order M; | 16 | * z is a root of unity of order M; |
| 16 | * G is a finitely generated subgroup of the multiplicative group Q* of Q; | 17 | * G is a finitely generated subgroup of the multiplicative group Q* of Q; |
| 17 | * G^{1/N} is the set of all elements x of an algebraic closure of Q such that | 18 | * G^1/N is the set of all elements x of an algebraic closure of Q such that |
| 18 | x^n belongs to G. | 19 | x^n belongs to G. |
| 19 | 20 | ||
| 20 | In other words, it is a number field generated by finitely many elements of | 21 | In other words, it is a number field generated by finitely many elements of |
| 21 | the form a^{1/n} and "at least sufficiently many" roots of unity to make | 22 | the form a^1/n and "at least sufficiently many" roots of unity to make |
| 22 | this field Galois over Q. | 23 | this field Galois over Q. |
| 23 | 24 | ||
| 24 | The main importance of this script is to show that, for a fixed group G as | 25 | The main importance of this script is to show that, for a fixed group G as |
| @@ -47,7 +48,7 @@ computation of degrees for the same group G only require constant time | |||
| 47 | 48 | ||
| 48 | ## KummerDegree( G, M, N ) | 49 | ## KummerDegree( G, M, N ) |
| 49 | 50 | ||
| 50 | Returns the degree of the Kummer extension Q_{M,N}=Q(\zeta_M,G^{1/N}) over Q. | 51 | Returns the degree of the Kummer extension Q{M,N}=Q(z,G^1/N ) over Q. |
| 51 | 52 | ||
| 52 | INPUT: | 53 | INPUT: |
| 53 | 54 | ||
| @@ -57,9 +58,10 @@ INPUT: | |||
| 57 | 58 | ||
| 58 | OUTPUT: | 59 | OUTPUT: |
| 59 | 60 | ||
| 60 | The degree of the Kummer Extensions Q_{M,N}=Q(\zeta_M,G^{1/N}) over Q. | 61 | The degree of the Kummer Extensions Q{M,N}=Q(z,G^1/N ) over Q. |
| 61 | 62 | ||
| 62 | EXAMPLES: | 63 | EXAMPLES: |
| 64 | |||
| 63 | ``` | 65 | ``` |
| 64 | sage: KummerDegree([5],10,2) | 66 | sage: KummerDegree([5],10,2) |
| 65 | 4 | 67 | 4 |
| @@ -80,8 +82,8 @@ G - a list of generators for the group G | |||
| 80 | 82 | ||
| 81 | OUPUT: | 83 | OUPUT: |
| 82 | 84 | ||
| 83 | The first part of the output consist of two positive integers M_0 and N_0. | 85 | The first part of the output consist of two positive integers M0 and N0. |
| 84 | N_0 is always a divisor of M_0. | 86 | N0 is always a divisor of M0. |
| 85 | 87 | ||
| 86 | The second part of the output can be either one or two tables, depending on | 88 | The second part of the output can be either one or two tables, depending on |
| 87 | the group G. In case -1 is not an element of G, there is only one table, | 89 | the group G. In case -1 is not an element of G, there is only one table, |
| @@ -155,6 +157,7 @@ M/N is ODD and is read as the previous one. | |||
| 155 | ``` | 157 | ``` |
| 156 | 158 | ||
| 157 | Uncommenting the line of code: | 159 | Uncommenting the line of code: |
| 160 | |||
| 158 | ``` | 161 | ``` |
| 159 | print_case_list( ret ) | 162 | print_case_list( ret ) |
| 160 | ``` | 163 | ``` |
