Langlands decomposition explained

P=MAN

of a reductive subgroup M, an abelian subgroup A, and a nilpotent subgroup N.

Applications

See also: Parabolic induction. A key application is in parabolic induction, which leads to the Langlands program: if

G

is a reductive algebraic group and

P=MAN

is the Langlands decomposition of a parabolic subgroup P, then parabolic induction consists of taking a representation of

MA

, extending it to

P

by letting

N

act trivially, and inducing the result from

P

to

G

.

See also

References

Sources