We study star operations for Iwahori-Hecke algebras and invariant hermitian
forms for finite dimensional modules over (graded) affine Hecke algebras with a
view towards a unitarity algorithm.Comment: 29 pages, preliminary version. v2: the classification of star
operations for the graded Hecke algebras and the construction of hermitian
forms in the Iwahori case via Bernstein's projectives have been removed from
this preprint and they will make the basis of a new pape