Query[MatrixAlgebra] - check if each matrix in a list of matrices belongs to a specified classical matrix algebra
Calling Sequences
Query(A, alg, options, "MatrixAlgebra")
Parameters
A - a list of square matrices, or a matrix representation of a Lie algebra
alg - a string, specifying a classical matrix algebra
options - (optional) keyword arguments output, quadraticform, skewform
Description
Examples
This query checks if a given list of matrices belongs to one of the following matrix algebras :
sln, sln,ℂ, sup, q, su∗n, un, son, son,ℂ, sop, q, so∗n, spn, ℝ, spp, q, spn, soln, niln.
For the definitions of all these matrix algebras see, SimpleLieAlgebraData.
with⁡DifferentialGeometry:with⁡LieAlgebras:
Example 1.
We check if each matrix in a list of matrices belongs to sl2.
A1≔Matrix⁡1,0,0,−1,Matrix⁡0,1,0,0,Matrix⁡0,0,1,0
Query⁡A1,sl(2),MatrixAlgebra
true
A2≔Matrix⁡1,0,0,−1,Matrix⁡1,1,0,0,Matrix⁡0,0,1,0
Query⁡A2,sl(2),MatrixAlgebra
false
With the keyword argument output = 'integer' , 0 is returned if all the matrices belong to the specified matrix algebra, otherwise the position of the first matrix which does not belong to the specified matrix algebra is returned.
Query⁡A1,sl(2),output=integer,MatrixAlgebra
0
Query⁡A2,sl(2),output=integer,MatrixAlgebra
2
Example 2.
We check if each matrix in list of matrices belong to so2,2. This is the Lie algebra of 4×4 matrices which are skew-symmetric with respect to a quadratic form of signature [2,2]. The default choice for the quadratic form is Q1 = 0I2I20. With the keyword argument version = 2, the quadratic form Q2 = I200−I2 is used. With the keyword argument quadraticform = M, the quadratic form M (a 4×4 symmetric matrix with signature [2, 2]) is used.
1. Default option.
B1≔map⁡Matrix,1,0,0,0,0,0,0,0,0,0,−1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,−1,0,0,0,0,0,1,0,0,0,0,0,0,−1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,−1,0,0,0,−1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,−1,0,0,1,0,0,0
Query⁡B1,so(2, 2),MatrixAlgebra
2. with version = 2.
B2≔map⁡Matrix,0,−1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,−1,0,0,1,0
Query⁡B2,so(2,2),version=2,MatrixAlgebra
3. with quadraticform = M
B3≔map⁡Matrix,1,0,0,0,0,−1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,−1,0,0,0,0,0,1,0,0,0,0,0,−1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,−1,0,0,0,0,0,0,0,0,0,0,1,−1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,−1
M≔Matrix⁡0,1,0,0,1,0,0,0,0,0,0,1,0,0,1,0
Query⁡B3,so(2, 2),quadraticform=M,MatrixAlgebra
Example 3.
We check if the members of a list of matrices belong to sp4, ℝ. This is the real Lie algebra of matrices which are skew-symmetric with respect to a skew-symmetric matrix J. The default choice is J =0In−In0. Other forms for J can be specified with the keyword argument skewform = J.
Here is the standard form of the matrices for sp4, ℝ.
C1≔map⁡Matrix,1,0,0,0,0,0,0,0,0,0,−1,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,−1,0,0,0,0,0,1,0,0,0,0,0,0,−1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,−1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0
Query⁡C1,sp(4, R),MatrixAlgebra
Define a skew-symmetric matrix J.
J≔Matrix⁡0,−1,0,0,1,0,0,0,0,0,0,1,0,0,−1,0
Here is the form of the matrices for sp4, ℝ with respect to J.
C2≔map⁡Matrix,−1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,−1,0,0,0,0,0,0,−1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,−1,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0
Query⁡C2,sp(4, R),skewform=J,MatrixAlgebra
Example 4.
Check that a list of matrices consists of upper triangular matrices.
D1≔map⁡Matrix,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,1
Query⁡D1,sol(3),MatrixAlgebra
Example 5.
Check that a list of matrices consists of nilpotent matrices.
E≔map⁡Matrix,−1,2,1,3,−1,2,1,3,1,−2,−1,−3,0,0,0,0,−1,3,2,4,−1,2,1,2,1,−4,−3,−6,0,1,1,2,0,1,1,0,0,1,1,0,0,−1,−1,0,0,0,0,0
Query⁡E,nil(4),MatrixAlgebra
LieAlgebraData⁡D1,NN
e1,e2=e2,e1,e3=e3,e2,e4=e2,e2,e5=e3,e3,e6=e3,e4,e5=e5,e5,e6=e5
Example 6.
Check that the following matrices define a Lie algebra and that this representation is unitary.
F≔map⁡Matrix,0,0,0,0,0,I,0,0,0,0,−I,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,I,0,0,0,0,−I,0,0,0,0,0,0,0,−1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,I,0,0,0,0,0,I,0,0
LD≔LieAlgebraData⁡F,alg
LD:=e1,e3=−e4,e1,e4=e3,e2,e3=−e4,e2,e4=e3,e3,e4=−2⁢e2−2⁢e1
DGsetup⁡LD
Lie algebra: alg
DGsetup⁡x1,x2,x3,V
frame name: V
ρ≔Representation⁡alg,V,F
Query⁡ρ,u(4),MatrixAlgebra
See Also
DifferentialGeometry
Query
Representation
SimpleLieAlgebraData
StandardRepresentation
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