Element structure of groups of order 81: Difference between revisions
No edit summary |
|||
| (2 intermediate revisions by the same user not shown) | |||
| Line 12: | Line 12: | ||
| [[Direct product of Z27 and Z3]] || 5 || 1 || [[element structure of direct product of Z27 and Z3]] | | [[Direct product of Z27 and Z3]] || 5 || 1 || [[element structure of direct product of Z27 and Z3]] | ||
|- | |- | ||
| [[ | | [[M81]] (semidirect product of Z27 and Z3)|| 6 || 2 || [[element structure of M81]] | ||
|- | |- | ||
| [[Wreath product of Z3 and Z3]] || 7 || 3 || [[element structure of wreath product of Z3 and Z3]] | | [[Wreath product of Z3 and Z3]] || 7 || 3 || [[element structure of wreath product of Z3 and Z3]] | ||
| Line 38: | Line 38: | ||
===Pairs where one of the groups is abelian=== | ===Pairs where one of the groups is abelian=== | ||
Of the 15 [[groups of order 81]], 5 are abelian, 6 have nilpotency class two, and 4 have nilpotency class three. Via the [[Baer correspondence]], each of the groups of class two has a Baer Lie ring, and in particular is 1-isomorphic to the additive group of that Lie ring. Of the 4 groups of nilpotency class three, only one ([[SmallGroup(81,8)]]) is 1- | Of the 15 [[groups of order 81]], 5 are abelian, 6 have nilpotency class two, and 4 have nilpotency class three. Via the [[Baer correspondence]], each of the groups of class two has a Baer Lie ring, and in particular is 1-isomorphic to the additive group of that Lie ring. Of the 4 groups of nilpotency class three, only one ([[SmallGroup(81,8)]]) is 1-isomorphic to an abelian group. There are ''no 1-isomorphisms between pairs where both members are non-abelian.'' | ||
{| class="sortable" border="1" | {| class="sortable" border="1" | ||
! Non-abelian member of pair !! Nilpotency class !! GAP ID !! Abelian member of pair !! GAP ID !! Nature of the 1-isomorphism !! Description of the 1-isomorphism !! Best perspective !! Alternative perspective | ! Non-abelian member of pair !! Nilpotency class !! GAP ID !! Abelian member of pair !! GAP ID !! Nature of the 1-isomorphism !! Description of the 1-isomorphism !! Best perspective !! Alternative perspective | ||
|- | |- | ||
| [[ | | [[M81]] || 2 || 6 || [[direct product of Z27 and Z3]] || 5 || [[Baer correspondence]] || [[Baer correspondence between M81 and its Lie ring]] || || | ||
|- | |- | ||
| [[nontrivial semidirect product of Z9 and Z9]] || 2 || 4 || [[direct product of Z9 and Z9]] || 2 || [[Baer correspondence | | [[nontrivial semidirect product of Z9 and Z9]] || 2 || 4 || [[direct product of Z9 and Z9]] || 2 || [[Baer correspondence ]] || [[Baer correspondence between nontriival semidirect product of Z9 and Z9 and its Lie ring]] || || | ||
|- | |- | ||
| [[SmallGroup(81,3)]] || 2 || 3 || [[direct product of Z9 and E9]] || 11 || [[Baer correspondence | | [[SmallGroup(81,3)]] || 2 || 3 || [[direct product of Z9 and E9]] || 11 || [[Baer correspondence]] || [[Baer correspondence between SmallGroup(81,3) and its Lie ring]] || || | ||
|- | |- | ||
| [[direct product of semidirect product of Z9 and Z3 and Z3]] || 2 || 13 || [[direct product of Z9 and E9]] || 11 || [[Baer correspondence | | [[direct product of semidirect product of Z9 and Z3 and Z3]] || 2 || 13 || [[direct product of Z9 and E9]] || 11 || [[Baer correspondence]] || [[Baer correspondence between direct product of semidirect product of Z9 and Z3 and Z3 and its Lie ring]] || || | ||
|- | |- | ||
| [[central product of prime-cube order group:U(3,3) and Z9]] || 2 || 14 || [[direct product of Z9 and E9]] || 11 || [[Baer correspondence | | [[central product of prime-cube order group:U(3,3) and Z9]] || 2 || 14 || [[direct product of Z9 and E9]] || 11 || [[Baer correspondence]] || [[Baer correspondence between central product of prime-cube order group:U(3,3) and Z9 and its Lie ring]] || || | ||
|- | |- | ||
| [[direct product of prime-cube order group:U(3,3) and Z3]] || 2 || 12 || [[elementary abelian group:E81]] || 15 || [[Baer correspondence | | [[direct product of prime-cube order group:U(3,3) and Z3]] || 2 || 12 || [[elementary abelian group:E81]] || 15 || [[Baer correspondence]] || [[Baer correspondence between direct product of prime-cube order group:U(3,3) and Z3 and its Lie ring]] || || | ||
|- | |- | ||
| [[SmallGroup(81,8)]] || 3 || 8 || [[direct product of Z9 and E9]] || 11 || ? || || || | | [[SmallGroup(81,8)]] || 3 || 8 || [[direct product of Z9 and E9]] || 11 || ? || || || | ||
| Line 65: | Line 65: | ||
| [[direct product of Z9 and Z9]] || 2 || 2 || [[nontrivial semidirect product of Z9 and Z9]] || 4 | | [[direct product of Z9 and Z9]] || 2 || 2 || [[nontrivial semidirect product of Z9 and Z9]] || 4 | ||
|- | |- | ||
| [[direct product of Z27 and Z3]] || 5 || 2 || [[ | | [[direct product of Z27 and Z3]] || 5 || 2 || [[M81]] || 6 | ||
|- | |- | ||
| [[direct product of Z9 and E9]] || 11 || 5 || [[SmallGroup(81,3)]], [[SmallGroup(81,8)]], [[direct product of semidirect product of Z9 and Z3 and Z3]], [[central product of prime-cube order group:U(3,3) and Z9]] || 3, 8, 13, 14 | | [[direct product of Z9 and E9]] || 11 || 5 || [[SmallGroup(81,3)]], [[SmallGroup(81,8)]], [[direct product of semidirect product of Z9 and Z3 and Z3]], [[central product of prime-cube order group:U(3,3) and Z9]] || 3, 8, 13, 14 | ||
| Line 95: | Line 95: | ||
| [[Direct product of Z27 and Z3]] || 5 || 1 || 8 || 18 || 54 || 0 | | [[Direct product of Z27 and Z3]] || 5 || 1 || 8 || 18 || 54 || 0 | ||
|- | |- | ||
| [[ | | [[M81]] || 6 || 1 || 8 || 18 || 54 || 0 | ||
|- | |- | ||
| [[Wreath product of Z3 and Z3]] || 7 || 1 || 44 || 36 || 0 || 0 | | [[Wreath product of Z3 and Z3]] || 7 || 1 || 44 || 36 || 0 || 0 | ||
| Line 144: | Line 144: | ||
| [[Direct product of Z27 and Z3]] || 5 || 1 || 9 || 27 || 81 || 81 | | [[Direct product of Z27 and Z3]] || 5 || 1 || 9 || 27 || 81 || 81 | ||
|- | |- | ||
| [[ | | [[M81]] || 6 || 1 || 9 || 27 || 81 || 81 | ||
|- | |- | ||
| [[Wreath product of Z3 and Z3]] || 7 || 1 || 45 || 81 || 81 || 81 | | [[Wreath product of Z3 and Z3]] || 7 || 1 || 45 || 81 || 81 || 81 | ||
| Line 191: | Line 191: | ||
| 1,2,6,18,54 || 1,3,9,27,81 || 1 || 1 || [[Cyclic group:Z81]] (ID:1) || -- || Yes || Yes | | 1,2,6,18,54 || 1,3,9,27,81 || 1 || 1 || [[Cyclic group:Z81]] (ID:1) || -- || Yes || Yes | ||
|- | |- | ||
| 1,8,18,54,0 || 1,9,27,81,81 || 2 || 1 || [[Direct product of Z27 and Z3]] (ID:5) and [[ | | 1,8,18,54,0 || 1,9,27,81,81 || 2 || 1 || [[Direct product of Z27 and Z3]] (ID:5) and [[M81]] (ID:6) || -- || Yes || Yes | ||
|- | |- | ||
| 1,8,72,0,0 || 1,9,81,81,81 || 3 || 2 || [[Direct product of Z9 and Z9]] (ID:2), [[Semidirect product of Z9 and Z9]] (ID:4) || [[SmallGroup(81,10)]] (ID:10) || Yes || Yes | | 1,8,72,0,0 || 1,9,81,81,81 || 3 || 2 || [[Direct product of Z9 and Z9]] (ID:2), [[Semidirect product of Z9 and Z9]] (ID:4) || [[SmallGroup(81,10)]] (ID:10) || Yes || Yes | ||
Latest revision as of 02:09, 20 July 2011
1-isomorphism
Pairs where one of the groups is abelian
Of the 15 groups of order 81, 5 are abelian, 6 have nilpotency class two, and 4 have nilpotency class three. Via the Baer correspondence, each of the groups of class two has a Baer Lie ring, and in particular is 1-isomorphic to the additive group of that Lie ring. Of the 4 groups of nilpotency class three, only one (SmallGroup(81,8)) is 1-isomorphic to an abelian group. There are no 1-isomorphisms between pairs where both members are non-abelian.
Grouping by abelian member
| Abelian member | GAP ID second part | Total number of members (including abelian member) | Other members | GAP IDs second part (in order of listing) |
|---|---|---|---|---|
| direct product of Z9 and Z9 | 2 | 2 | nontrivial semidirect product of Z9 and Z9 | 4 |
| direct product of Z27 and Z3 | 5 | 2 | M81 | 6 |
| direct product of Z9 and E9 | 11 | 5 | SmallGroup(81,3), SmallGroup(81,8), direct product of semidirect product of Z9 and Z3 and Z3, central product of prime-cube order group:U(3,3) and Z9 | 3, 8, 13, 14 |
| elementary abelian group:E81 | 15 | 2 | direct product of prime-cube order group:U(3,3) and Z3 | 12 |
Groupings that do not have any abelian members
There are no 1-isomorphisms between pairs where both members are non-abelian for order 81. Thus, there are no such groupings.
Order statistics
FACTS TO CHECK AGAINST:
ORDER STATISTICS (cf. order statistics, order statistics-equivalent finite groups): number of nth roots is a multiple of n | Finite abelian groups with the same order statistics are isomorphic | Lazard Lie group has the same order statistics as the additive group of its Lazard Lie ring | Frobenius conjecture on nth roots
1-ISOMORPHISM (cf. 1-isomorphic groups): Lazard Lie group is 1-isomorphic to the additive group of its Lazard Lie ring | order statistics-equivalent not implies 1-isomorphic
Order statistics raw data
| Group | Second part of GAP ID | Number of elements of order 1 | Number of elements of order 3 | Number of elements of order 9 | Number of elements of order 27 | Number of elements of order 81 |
|---|---|---|---|---|---|---|
| Cyclic group:Z81 | 1 | 1 | 2 | 6 | 18 | 54 |
| Direct product of Z9 and Z9 | 2 | 1 | 8 | 72 | 0 | 0 |
| SmallGroup(81,3) | 3 | 1 | 26 | 54 | 0 | 0 |
| Nontrivial semidirect product of Z9 and Z9 | 4 | 1 | 8 | 72 | 0 | 0 |
| Direct product of Z27 and Z3 | 5 | 1 | 8 | 18 | 54 | 0 |
| M81 | 6 | 1 | 8 | 18 | 54 | 0 |
| Wreath product of Z3 and Z3 | 7 | 1 | 44 | 36 | 0 | 0 |
| SmallGroup(81,8) | 8 | 1 | 26 | 54 | 0 | 0 |
| SmallGroup(81,9) | 9 | 1 | 62 | 18 | 0 | 0 |
| SmallGroup(81,10) | 10 | 1 | 8 | 72 | 0 | 0 |
| Direct product of Z9 and E9 | 11 | 1 | 26 | 54 | 0 | 0 |
| Direct product of prime-cube order group:U(3,3) and Z3 | 12 | 1 | 80 | 0 | 0 | 0 |
| Direct product of semidirect product of Z9 and Z3 and Z3 | 13 | 1 | 26 | 54 | 0 | 0 |
| SmallGroup(81,14) | 14 | 1 | 26 | 54 | 0 | 0 |
| Elementary abelian group:E81 | 15 | 1 | 80 | 0 | 0 | 0 |
Here is the GAP code to generate these order statistics:[SHOW MORE]
Here are the cumulative order statistics.
| Group | Second part of GAP ID | Number of 1st roots | Number of 3rd roots | Number of 9th roots | Number of 27th roots | Number of 81th roots |
|---|---|---|---|---|---|---|
| Cyclic group:Z81 | 1 | 1 | 3 | 9 | 27 | 81 |
| Direct product of Z9 and Z9 | 2 | 1 | 9 | 81 | 81 | 81 |
| SmallGroup(81,3) | 3 | 1 | 27 | 81 | 81 | 81 |
| Nontrivial semidirect product of Z9 and Z9 | 4 | 1 | 9 | 81 | 81 | 81 |
| Direct product of Z27 and Z3 | 5 | 1 | 9 | 27 | 81 | 81 |
| M81 | 6 | 1 | 9 | 27 | 81 | 81 |
| Wreath product of Z3 and Z3 | 7 | 1 | 45 | 81 | 81 | 81 |
| SmallGroup(81,8) | 8 | 1 | 27 | 81 | 81 | 81 |
| SmallGroup(81,9) | 9 | 1 | 63 | 81 | 81 | 81 |
| SmallGroup(81,10) | 10 | 1 | 9 | 81 | 81 | 81 |
| Direct product of Z9 and E9 | 11 | 1 | 27 | 81 | 81 | 81 |
| Direct product of prime-cube order group:U(3,3) and Z3 | 12 | 1 | 81 | 81 | 81 | 81 |
| Direct product of semidirect product of Z9 and Z3 and Z3 | 13 | 1 | 27 | 81 | 81 | 81 |
| SmallGroup(81,14) | 14 | 1 | 27 | 81 | 81 | 81 |
| Elementary abelian group:E81 | 15 | 1 | 81 | 81 | 81 | 81 |
Here is the GAP code to generate these cumulative order statistics:[SHOW MORE]
Equivalence classes based on order statistics
Here, we discuss the equivalence classes of groups of order 81 up to being order statistics-equivalent finite groups and up to the stronger notion of being 1-isomorphic groups (which means there is a bijection that restricts to isomorphisms on cyclic subgroups). See also order statistics-equivalent not implies 1-isomorphic.
| Order statistics | Order statistics (cumulative) | Number of groups | Number of equivalence classes up to 1-isomorphism | Members of first equivalence class | Members of second equivalence class | Abelian group with these order statistics? | Cumulative order statistics all powers of 3? |
|---|---|---|---|---|---|---|---|
| 1,2,6,18,54 | 1,3,9,27,81 | 1 | 1 | Cyclic group:Z81 (ID:1) | -- | Yes | Yes |
| 1,8,18,54,0 | 1,9,27,81,81 | 2 | 1 | Direct product of Z27 and Z3 (ID:5) and M81 (ID:6) | -- | Yes | Yes |
| 1,8,72,0,0 | 1,9,81,81,81 | 3 | 2 | Direct product of Z9 and Z9 (ID:2), Semidirect product of Z9 and Z9 (ID:4) | SmallGroup(81,10) (ID:10) | Yes | Yes |
| 1,26,54,0,0 | 1,27,81,81,81 | 5 | 1 or 2 | Direct product of Z9 and E9 (ID:11), SmallGroup(81,3) (ID:3), Direct product of semidirect product of Z9 and Z3 and Z3 (ID:13), Central product of prime-cube order group:U(3,3) and Z9 (ID:14), SmallGroup(81,8) (ID:8) | Yes | Yes | |
| 1,44,36,0,0 | 1,45,81,81,81 | 1 | 1 | Wreath product of Z3 and Z3 (ID:7) | -- | No | No |
| 1,62,18,0,0 | 1,63,81,81,81 | 1 | 1 | SmallGroup(81,9) (ID:9) | -- | No | No |
| 1,80,0,0,0 | 1,81,81,81,81 | 2 | 1 | Elementary abelian group:E81 (ID:15) and Direct product of prime-cube order group:U(3,3) and Z3 (ID:12) | -- | Yes | Yes |