We give a brief survey on some new developments on elliptic operators on manifolds with polyhedral singularities. The material essentially corresponds to a talk given by the author during the Conference "Elliptic and Hyperbolic Equations on Singular Spaces", October 27 -31, 2008, at the MSRI, University of Berkeley.
Mathematics Subject Classification:Primary: 35S35 Secondary: 35J70 Keywords: Categories of stratified spaces, ellipticity of corners operators, principal symbolic hierarchies, boundary value problems, parametrices in algebras of corner operators Boundary symbols are homogeneous in the senseHere κ λ : H s (R + ) → H s−m (R + ) is a strongly continuous group of isomorphisms, defined by (κ λ u)(r) := λ 1/2 u(λr), λ ∈ R + . A similar relation holds for edge symbols, based onIn this presentation we give an idea on how to formulate algebras of (pseudo-differential) operators on int M that contain the (for the nature of singularities typical) differential operators, together with the parametrices of elliptic elements. More details may be found in [45], [46], and in a new monograph in preparation [47], see also the references below. 2 1 The category M k Stratified spaces of different kind occur in numerous fields of mathematics and also in the applied sciences. Here we single out specific categories of such spaces where certain elements of the analysis of PDE can be formulated in an iterative manner. General references on stratified spaces are Fulton and MacPherson [14], or Weinberger [57]. Definition 1.1. A topological space M (under some natural conditions on the topology in general ) is said to be a manifold with singularities of order k ∈ N, k ≥ 1, ifTransition maps X ∆ → X ∆ are induced by restrictions of M k−1 -isomorphisms R×X → R×X to R + × X. This gives rise to corresponding transition maps X ∆ × Ω → X ∆ ×Ω for the respective X ∆ -bundles over Y .Remark 1.2. M k is a category with a natural notion of morphisms and isomorphisms.as a disjoint union of strata Y j ∈ M 0 . We set int M := Y 0 , called the maximal stratum of M, and dim M := dim(int M ). Moreover, M is locally near Y j modelled on an X ∆ j−1 -bundle over Y j , forRemark 1.4. The same topological space M can be stratified in different ways. For instance, we have M = R n ∈ M 0 but also M ∈ M 1 when we setThere are many other interesting properties of the categories M k that we do not discuss in detail here. It would be desirable to develop the connection of our analysis on singular spaces with the work from topological side. For instance, D. Trotman informed me in Berkeley on his works with coauthors, cf.[3] jointly with Bekka, and [23] with King.
AbstractWe give a brief survey on some new developments on elliptic operators on manifolds with polyhedral singularities. The material essentially corresponds to a talk given by the author during the Conference "