In
mathematics, restricted root systems, sometimes called relative root systems, are the
root systems associated with a
symmetric space. The associated finite reflection group is called the restricted Weyl group. The restricted root system of a symmetric space and its dual can be identified. For symmetric spaces of noncompact type arising as homogeneous spaces of a semisimple
Lie group, the restricted root system and its Weyl group are related to the
Iwasawa decomposition of the Lie group.
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ISBN9783540546832
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ISBN0821852825