Invariant Differential Operators for Non-Compact Lie Groups: Parabolic Subalgebras

In the present paper we start the systematic explicit construction of invariant differential operators by giving explicit description of one of the main ingredients - the cuspidal parabolic subalgebras. We explicate also the maximal parabolic subalgebras, since these are also important even when they are not cuspidal. Our approach is easily generalised to the supersymmetric and quantum group settings and is necessary for applications to string theory and integrable models.Comment: 44 pages; V2: important addition in Section 3 and misprints corrected; more corrections in Section 3; v3-v6: various corrections; v7: corrections in (11.7),(11.9),(11.11), and correspondingly in the Appendix; v8: added dimensions of N-factors where missing; v9: added missing case in 11.37; v10: corrected misprint in 11.17; v11: added missing case in 11.37; v12: typos corrected in (11.7),(11.9

Exceptional Lie Algebra E7(−25)E_{7(-25)} (Multiplets and Invariant Differential Operators)

In the present paper we continue the project of systematic construction of invariant differential operators on the example of the non-compact exceptional algebra $E_{7(-25)}$. Our choice of this particular algebra is motivated by the fact that it belongs to a narrow class of algebras, which we call 'conformal Lie algebras', which have very similar properties to the conformal algebras of $n$-dimensional Minkowski space-time. This class of algebras is identified and summarized in a table. Another motivation is related to the AdS/CFT correspondence. We give the multiplets of indecomposable elementary representations, including the necessary data for all relevant invariant differential operators.Comment: 20 pages, 2 figures, TEX with input files harvmac.tex, amssym.def, amssym.tex; v2: added references; v3: change of normalization in f-lae (4.1) and (4.7