Non-Commutative Kirillov Method and Coadjoint Orbits

Publication Type:
Thesis
Issue Date:
2024
Full metadata record
Elie Cartan and Hermann Weyl’s theorem of highest weight states that every irreducible highest weight representation of a compact real form of a complex semisimple Lie algebra, integrates to an irreducible highest weight representation of a compact, simply connected, semisimple Lie group. However, there is no explicit computation method for this correspondence. Based on the work of Raed Raffoul, we combine the Kirillov orbit method, the sum of adjoint orbits, the convexity theorem for moment maps, Nelson’s formula for Weyl calculus, and the transversality condition and induced differential operators, to develop a non-commutative Kirillov method. This framework allows us to explicitly compute the exponential of irreducible highest weight representations of compact semisimple Lie algebras. It also enables the lift of invariant vector fields, arising from root vectors in the complex semisimple Lie algebras, to differential operators induced by the adjoint action of the group, with respect to the lift of matrix coefficients. Moreover, we show that the Euclidean Fourier transform of the lift of highest weight representations consists of polynomials of transversal differential operators acting on an invariant measure supported on the image of the moment map of the representation, in the dual Lie algebra.
Please use this identifier to cite or link to this item: