LieAlgebras[GradeSemiSimpleLieAlgebra] - find the grading of a semi-simple Lie algebra defined by a set of simple roots or restricted simple roots
Calling Sequences
GradeSemiSimpleLieAlgebra(1)
GradeSemiSimpleLieAlgebra(2, method = "non-compact")
Parameters
Sigma - a list or set of column vectors, defining a subset of the simple roots or a subset of the restricted simple roots
T1 - a table, with indices that include "RootSpaceDecomposition", "CartanSubalgebra", "SimpleRoots", "PositiveRoots"
T2 - a table, with indices that include "RestrictedRoot SpaceDecomposition", "CartanSubalgebraDecomposition", "RestrictedSimpleRoots", "RestrictedPositiveRoots"
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Description
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and
define a (symmetric) grading g =
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The command Query/"Gradation" will test if a given decomposition of a Lie algebra is graded.
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Examples
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Example 1.
We calculate the various gradations for We use the command SimpleLieAlgebraData to initialize the Lie algebra.
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| (2.1) |
sl4 >
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We use the command SimpleLieAlgebraProperties to create a table containing the structure properties of .
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sl4 >
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Here are the possible subsets of the set of simple roots.
sl4 >
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Here are the gradings defined by each subset of the simple roots.
sl4 >
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sl4 >
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sl4 >
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sl4 >
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sl4 >
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sl4 >
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sl4 >
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| (2.10) |
sl4 >
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| (2.11) |
sl4 >
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The Query command can be used to check that each of these define a grading of .
sl4 >
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| (2.13) |
sl4 >
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Example 2.
We calculate the various gradings for We use the command SimpleLieAlgebraData to initialize the Lie algebra.
sl4 >
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sl4 >
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We use the command SimpleLieAlgebraProperties to calculate the restricted root space decomposition, restricted simple roots, etc.
so53 >
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so53 >
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| (2.16) |
The subsets of the restricted simple roots are:
so53 >
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Here are the possible gradings for
so53 >
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| (2.17) |
so53 >
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| (2.18) |
so53 >
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| (2.19) |
so53 >
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| (2.20) |
so53 >
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| (2.21) |
so53 >
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| (2.22) |
so53 >
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| (2.23) |
so53 >
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| (2.24) |
The Query command can be used to check that each of these define a grading of .
so53 >
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| (2.25) |
so53 >
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| (2.26) |
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See Also
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DifferentialGeometry,
CartanSubalgebra, KillingForm, LieAlgebras, PositiveRoots, Query, SimpleRoots, RootSpaceDecomposition, RestrictedRootSpaceDecomposition,
SimpleLieAlgebraData, SimpleLieAlgebraProperties
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