2003/04/20 by Richard Melrose, Melrose, Richard, Frédéric Rochon +2
Mathematics · #Advanced Operator Algebra Research #Holomorphic and Operator Theory #Spectral Theory in Mathematical Physics #math.AP #math.DG #msc:58J20 #msc:58J40
paper · pdf · doi:10.48550/arxiv.math/0304280
21 pages; corrected typos, changed the abstract, added a paragraph in the introduction
arxiv created 2003/11/20 · arxiv updated 2009/11/30
An analytic index is defined for a family of cusp pseudodifferential operators, Pb, on a fibration with fibres which are compact manifolds with boundaries, provided the family is elliptic and has invertible indicial family at the boundary. In fact there is always a perturbation Qb by a family of cusp operators of order -∞ such that each Pb+Qb is invertible. Thus any elliptic family of symbols has a realization as an invertible family of cusp pseudodifferential operators, which is a form of the cobordism invariance of the index. A crucial role is played by the weak contractibility of the group of cusp smoothing operators on a compact manifold with non-trivial boundary and the associated exact sequence of classifying spaces of odd and even K-theory.