Package sage :: Package groups :: Package matrix_gps :: Module unitary
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Module unitary

source code


Unitary Groups $GU(n,q)$ and $SU(n,q)$

These are $n \times n$ unitary matrices with entries in $GF(q^2)$.

AUTHOR:
    -- David Joyner (2006-03): initial version, modified from 
                     special_linear (by W. Stein)
    -- David Joyner (2006-05): minor additions (examples, _latex_,
                                            __str__, gens)
    -- William Stein (2006-12) -- rewrite
    
EXAMPLES:
    sage: G = SU(3,GF(5))
    sage: G.order()
    378000
    sage: G
    Special Unitary Group of degree 3 over Finite Field of size 5
    sage: G._gap_init_()
    'SU(3, 5)'
    sage: G.random_element()
    [      1 4*a + 4 4*a + 1]
    [2*a + 4 2*a + 1       0]
    [      4     3*a 4*a + 2]
    sage: G.base_ring()
    Finite Field of size 5
    sage: G.field_of_definition()
    Finite Field in a of size 5^2



Classes [hide private]
  UnitaryGroup_finite_field
  GeneralUnitaryGroup_finite_field
  SpecialUnitaryGroup_finite_field
Functions [hide private]
 
GU(n, F, var='a')
Return the general unitary group of degree n over the finite field F.
source code
 
SU(n, F, var='a')
Return the special unitary group of degree $n$ over $F$.
source code
Function Details [hide private]

GU(n, F, var='a')

source code 

Return the general unitary group of degree n over the finite field F.

INPUT:
    n -- a positive integer
    F -- finite field
    var -- variable used to represent generator of quadratic
           extension of F, if needed.

EXAMPLES:
    sage: G = GU(3,GF(7)); G
    General Unitary Group of degree 3 over Finite Field of size 7
    sage: G.gens()
    [
    [  a   0   0]
    [  0   1   0]
    [  0   0 5*a],
    [6*a   6   1]
    [  6   6   0]
    [  1   0   0]
    ]
    sage: G = GU(2,QQ)
    Traceback (most recent call last):
    ...
    NotImplementedError: general unitary group only implemented over finite fields

    sage: G = GU(3,GF(5), var='beta')
    sage: G.gens()
    [
    [  beta      0      0]
    [     0      1      0]
    [     0      0 3*beta],
    [4*beta      4      1]
    [     4      4      0]
    [     1      0      0]
    ]        

SU(n, F, var='a')

source code 

Return the special unitary group of degree $n$ over $F$.

EXAMPLES:
    sage: SU(3,5)
    Special Unitary Group of degree 3 over Finite Field of size 5
    sage: SU(3,QQ)
    Traceback (most recent call last):
    ...
    NotImplementedError: special unitary group only implemented over finite fields