DifferentialGeometry/LieAlgebras/Query/Closed UnderConjugate - Maple Help
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Query[ClosedUnderConjugation] - check if a list of vectors or matrices is closed under complex conjugation

Query[ClosedUnderTransposition] - check if a list of square matrices is closed under transposition

Query[ClosedUnderHermitianTransposition] - check if a list of square matrices is closed under Hermitian (complex conjugation) transposition

Calling Sequences

     Query(A, options , ClosedUnderConjugation)

     Query(A, options , ClosedUnderTransposition)

     Query(A, options , ClosedUnderHermitianTransposition)

Parameters

     A       - a list of column vectors, or a list of square matrices

     option  - the keyword method

 

Description

Examples

Description

• 

Let A  = A1,  A2, ... , Am be a list of square matrices. These query commands return true if for each i,  FAi = Aki  for some ki ,  where  FA = A (conjugation) or  FA = At (transposition) or FA = A(Hermitian transposition).

• 

With the keyword option method = "span", these commands return true if for each  i,  FAi  span(A).

• 

These commands are useful in the study of classical semi-simple Lie algebras. For example, if a semi-simple matrix Lie algebra is given, then a Cartan decomposition can easily be computed if the algebra is closed under Hermitian transposition. As another example, to calculate the Satake diagram for a non-compact simple Lie algebra, one must use a set of positive roots closed under complex conjugation.

Examples

withDifferentialGeometry:withLieAlgebras:

 

Example 1.

We check that a list of vectors is closed under complex-conjugation.

 

A1I,I,1,0,1,0,I,I,1

QueryA1,ClosedUnderConjugation

 

Example 2.

We check that the list of matrices defining so2,2 is closed under transposition.

A2mapMatrix,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

QueryA2,ClosedUnderTransposition

 

Example 3.

We check that the span of the matrices defining so4 is closed under Hermitian transposition.

A3mapMatrix,0,1,0,0,1,0,0,0,0,0,0,1,0,0,1,0,0,I,0,0,I,0,0,0,0,0,0,I,0,0,I,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,1,0,0,1,0,0,1,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,I,0,0,I,0,0,I,0,0,I,0,0,0

QueryA3,ClosedUnderHermitianTransposition

QueryA3,method=span,ClosedUnderHermitianTransposition

 

 

See Also

DifferentialGeometry

CartanDecomposition

LieAlgebras

Query

SatakeDiagram