6533b7d8fe1ef96bd126994d

RESEARCH PRODUCT

Fixpunktmengen von halbeinfachen Automorphismen in halbeinfachen Lie-Algebren

Klaus Pommerening

subject

Pure mathematicsGeneral MathematicsSubalgebraCartan subalgebra510 MathematikFixed pointAutomorphism510 MathematicsInner automorphismMathematics::Quantum AlgebraBounded functionAlgebraically closed fieldMathematics::Representation TheorySemisimple Lie algebraMathematics

description

Let g be a semisimple Lie algebra over an algebraically closed field of characteristic 0. The set of fixed points of a semisimple inner automorphism of g is a regular reductive subalgebra of maximal rank [1], so it is defined by a subsystem of the root system Φ of g relative to a suitable Cartan subalgebra. The main theorem of the article characterizes the corresponding subsystems of Φ. The second part of the article shows how to compute the fixed point algebras of semisimple outer automorphisms of g. A complete list of all fixed point algebras is then easily obtainable. The results are applied to bounded symmetric domains. References

https://dx.doi.org/10.25358/openscience-513