algebraic cone; monoid action; group action; orbit; action with unique fixed point; algebra automorphism; stable ideal; irreducible algebraic variety normal complexes; restriction; adjunction; primitive pairs; inner product formula; purity; blocks; complex reductive group; complex algebraic variety; perverse sheaves; nilpotent orbits; parabolic subalgebra; Fourier-Deligne transform; Fourier transform; quasi-monomial objects; isomorphism; Lagrangian variety 