Projective pseudodifferential analysis and harmonic analysis

We consider pseudodifferential operators on functions on Rn+1 which commute with the Euler operator, and can thus be restricted to spaces of functions homogeneous of some given degree. The symbols of such restrictions can be regarded as functions on a reduced phase space, isomorphic to the homogeneous space Gn/Hn = SL(n + 1,R)/GL(n,R), and the resulting calculus is a pseudodifferential analysis of operators acting on spaces of appropriate sections of line bundles over the projective space Pn(R): these spaces are the representation spaces of the maximal degenerate series (πiλ,ε) ofGn. This new approach to the quantization of Gn/Hn, already considered by other authors, has several advantages: as an example, it makes it possible to give a very explicit version of the continuous part from the decomposition of L2(Gn/Hn) under the quasiregular action of Gn.We also consider interesting special symbols, which arise from the consideration of the resolvents of certain infinitesimal operators of the representation πiλ,ε. © 2006 Elsevier Inc. All rights reserved