Invariant Differential Operators for Non-Compact Lie Groups: the Reduced SU(3,3) Multiplets

In the present paper we continue the project of systematic construction of invariant differential operators on the example of the non-compact algebras $su(n,n)$. Earlier were given the main multiplets of indecomposable elementary representations for $n\leq 4$, and the reduced ones for $n=2$. Here we give all reduced multiplets containing physically relevant representations including the minimal ones for the algebra $su(3,3)$. Due to the recently established parabolic relations the results are valid also for the algebra $sl(6,\mathbb{R})$ with suitably chosen maximal parabolic subalgebra.