@unpublished{SavinSchulzeSternin1998, author = {Savin, Anton and Schulze, Bert-Wolfgang and Sternin, Boris}, title = {On the invariant index formulas for spectral boundary value problems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25285}, year = {1998}, abstract = {In the paper we study the possibility to represent the index formula for spectral boundary value problems as a sum of two terms, the first one being homotopy invariant of the principal symbol, while the second depends on the conormal symbol of the problem only. The answer is given in analytical, as well as in topological terms.}, language = {en} } @unpublished{SavinSchulzeSternin2000, author = {Savin, Anton and Schulze, Bert-Wolfgang and Sternin, Boris}, title = {Elliptic operators in subspaces}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25701}, year = {2000}, abstract = {We construct elliptic theory in the subspaces, determined by pseudodifferential projections. The finiteness theorem as well as index formula are obtained for elliptic operators acting in the subspaces. Topological (K-theoretic) aspects of the theory are studied in detail.}, language = {en} } @unpublished{SavinSternin2000, author = {Savin, Anton and Sternin, Boris}, title = {Eta-invariant and Pontrjagin duality in K-theory}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25747}, year = {2000}, abstract = {The topological significance of the spectral Atiyah-Patodi-Singer η-invariant is investigated. We show that twice the fractional part of the invariant is computed by the linking pairing in K-theory with the orientation bundle of the manifold. The Pontrjagin duality implies the nondegeneracy of the linking form. An example of a nontrivial fractional part for an even-order operator is presented.}, language = {en} } @unpublished{SavinSternin2000, author = {Savin, Anton and Sternin, Boris}, title = {Eta invariant and parity conditions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25869}, year = {2000}, abstract = {We give a formula for the η-invariant of odd order operators on even-dimensional manifolds, and for even order operators on odd-dimensional manifolds. Geometric second order operators are found with nontrivial η-invariants. This solves a problem posed by P. Gilkey.}, language = {en} } @unpublished{SavinSternin1999, author = {Savin, Anton and Sternin, Boris}, title = {Elliptic operators in even subspaces}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25461}, year = {1999}, abstract = {An elliptic theory is constructed for operators acting in subspaces defined via even pseudodifferential projections. Index formulas are obtained for operators on compact manifolds without boundary and for general boundary value problems. A connection with Gilkey's theory of η-invariants is established.}, language = {en} } @unpublished{SavinSternin2005, author = {Savin, Anton and Sternin, Boris}, title = {Pseudodifferential subspaces and their applications in elliptic theory}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-29937}, year = {2005}, abstract = {The aim of this paper is to explain the notion of subspace defined by means of pseudodifferential projection and give its applications in elliptic theory. Such subspaces are indispensable in the theory of well-posed boundary value problems for an arbitrary elliptic operator, including the Dirac operator, which has no classical boundary value problems. Pseudodifferential subspaces can be used to compute the fractional part of the spectral Atiyah-Patodi-Singer eta invariant, when it defines a homotopy invariant (Gilkey's problem). Finally, we explain how pseudodifferential subspaces can be used to give an analytic realization of the topological K-group with finite coefficients in terms of elliptic operators. It turns out that all three applications are based on a theory of elliptic operators on closed manifolds acting in subspaces.}, language = {en} } @unpublished{SavinSternin1999, author = {Savin, Anton and Sternin, Boris}, title = {Elliptic operators in odd subspaces}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25478}, year = {1999}, abstract = {An elliptic theory is constructed for operators acting in subspaces defined via even pseudodifferential projections. Index formulas are obtained for operators on compact manifolds without boundary and for general boundary value problems. A connection with Gilkey's theory of η-invariants is established.}, language = {en} } @unpublished{SavinSternin2001, author = {Savin, Anton and Sternin, Boris}, title = {Index defects in the theory of nonlocal boundary value problems and the η-invariant}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26146}, year = {2001}, abstract = {The paper deals with elliptic theory on manifolds with boundary represented as a covering space. We compute the index for a class of nonlocal boundary value problems. For a nontrivial covering, the index defect of the Atiyah-Patodi-Singer boundary value problem is computed. We obtain the Poincar{\´e} duality in the K-theory of the corresponding manifolds with singularities.}, language = {en} } @unpublished{Schrohe2000, author = {Schrohe, Elmar}, title = {A short introduction to Boutet de Monvel's calculus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25696}, year = {2000}, abstract = {This paper provides an introduction to Boutet de Monvel's calculus on the half-space IRn (positiv) in the framework of a pseudodifferential calculus with operator-valued symbols.}, language = {en} } @unpublished{Schrohe1999, author = {Schrohe, Elmar}, title = {Noncommutative residues, Dixmier's Trace, and heat trace expansions on manifolds with boundary}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25486}, year = {1999}, abstract = {For manifolds with boundary, we define an extension of Wodzicki's noncommutative residue to boundary value problems in Boutet de Monvel's calculus. We show that this residue can be recovered with the help of heat kernel expansions and explore its relation to Dixmier's trace.}, language = {en} } @unpublished{SchroheSchulze1999, author = {Schrohe, Elmar and Schulze, Bert-Wolfgang}, title = {Edge-degenerate boundary value problems on cones}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25436}, year = {1999}, abstract = {We consider edge-degenerate families of pseudodifferential boundary value problems on a semi-infinite cylinder and study the behavior of their push-forwards as the cylinder is blown up to a cone near infinity. We show that the transformed symbols belong to a particularly convenient symbol class. This result has applications in the Fredholm theory of boundary value problems on manifolds with edges.}, language = {en} } @unpublished{SchroheSeiler1999, author = {Schrohe, Elmar and Seiler, J{\"o}rg}, title = {Ellipticity and invertibility in the cone algebra on Lp-Sobolev spaces}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25621}, year = {1999}, abstract = {Given a manifold B with conical singularities, we consider the cone algebra with discrete asymptotics, introduced by Schulze, on a suitable scale of Lp-Sobolev spaces. Ellipticity is proven to be equivalent to the Fredholm property in these spaces, it turns out to be independent of the choice of p. We then show that the cone algebra is closed under inversion: whenever an operator is invertible between the associated Sobolev spaces, its inverse belongs to the calculus. We use these results to analyze the behaviour of these operators on Lp(B).}, language = {en} } @unpublished{SchroheSeiler2002, author = {Schrohe, Elmar and Seiler, J{\"o}rg}, title = {The resolvent of closed extensions of cone differential operators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26378}, year = {2002}, abstract = {We study an elliptic differential operator on a manifold with conical singularities, acting as an unbounded operator on a weighted Lp-space. Under suitable conditions we show that the resolvent (λ - A )-¹ exists in a sector of the complex plane and decays like 1/|λ| as |λ| -> ∞. Moreover, we determine the structure of the resolvent with enough precision to guarantee existence and boundedness of imaginary powers of A. As an application we treat the Laplace-Beltrami operator for a metric with striaght conical degeneracy and establish maximal regularity for the Cauchy problem u - Δu = f, u(0) = 0.}, language = {en} } @unpublished{SchroheWalzeWarzecha1998, author = {Schrohe, Elmar and Walze, Markus and Warzecha, Jan-Martin}, title = {Construction de Triplets Spectraux {\`a} Partir de Modules de Fredholm}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-25247}, year = {1998}, abstract = {Soit (A, H, F) un module de Fredholm p-sommable, o{\`u} l'alg{\`e}bre A = CT est engendr{\´e}e par un groupe discret Gamma d'{\´e}l{\´e}ments unitaires de L(H) qui est de croissance polynomiale r. On construit alors un triplet spectral (A, H, D) sommabilit{\´e} q pour tout q > p + r + 1 avec F = signD. Dans le cas o{\`u} (A, H, F) est (p, infini)-sommable on obtient la (q, infini)-sommabilit{\´e} de (A, H, D)pour tout q > p + r + 1.}, language = {fr} } @unpublished{Schulze2003, author = {Schulze, Bert-Wolfgang}, title = {Crack theory with singularties at the boundary}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26600}, year = {2003}, abstract = {We investigate crack problems, where the crack boundary has conical singularities. Elliptic operators with two-sided elliptc boundary conditions on the plus and minus sides of the crack will be interpreted as elements of a corner algebra of boundary value problems. The corresponding operators will be completed by extra edge conditions on the crack boundary to Fredholm operators in corner Sobolev spaces with double weights, and there are parametrices within the calculus.}, language = {en} } @unpublished{Schulze2006, author = {Schulze, Bert-Wolfgang}, title = {Pseudo-differential calculus on manifolds with geometric singularities}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30204}, year = {2006}, abstract = {Differential and pseudo-differential operators on a manifold with (regular) geometric singularities can be studied within a calculus, inspired by the concept of classical pseudo-differential operators on a C1 manifold. In the singular case the operators form an algebra with a principal symbolic hierarchy σ = (σj)0≤j≤k, with k being the order of the singularity and σk operator-valued for k ≥ 1. The symbols determine ellipticity and the nature of parametrices. It is typical in this theory that, similarly as in boundary value problems (which are special edge problems, where the edge is just the boundary), there are trace, potential and Green operators, associated with the various strata of the configuration. The operators, obtained from the symbols by various quantisations, act in weighted distribution spaces with multiple weights. We outline some essential elements of this calculus, give examples and also comment on new challenges and interesting problems of the recent development.}, language = {en} } @unpublished{Schulze2009, author = {Schulze, Bert-Wolfgang}, title = {Boundary value problems with the transmission property}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30377}, year = {2009}, abstract = {We give a survey on the calculus of (pseudo-differential) boundary value problems with the transmision property at the boundary, and ellipticity in the Shapiro-Lopatinskij sense. Apart from the original results of the work of Boutet de Monvel we present an approach based on the ideas of the edge calculus. In a final section we introduce symbols with the anti-transmission property.}, language = {en} } @unpublished{Schulze2008, author = {Schulze, Bert-Wolfgang}, title = {The iterative structure of corner operators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30353}, year = {2008}, abstract = {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.}, language = {en} } @unpublished{Schulze2006, author = {Schulze, Bert-Wolfgang}, title = {Elliptic differential operators on manifolds with edges}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30188}, year = {2006}, abstract = {On a manifold with edge we construct a specific class of (edgedegenerate) elliptic differential operators. The ellipticity refers to the principal symbolic structure σ = (σψ, σ^) of the edge calculus consisting of the interior and edge symbol, denoted by σψ and σ^, respectively. For our choice of weights the ellipticity will not require additional edge conditions of trace or potential type, and the operators will induce isomorphisms between the respective edge spaces.}, language = {en} } @unpublished{Schulze2008, author = {Schulze, Bert-Wolfgang}, title = {On a paper of Krupchyk, Tarkhanov, and Tuomela}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-30325}, year = {2008}, language = {en} }