@unpublished{LiuYangLu2002, author = {Liu, Weian and Yang, Yin and Lu, Gang}, title = {Viscosity solutions of fully nonlinear parabolic systems}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26215}, year = {2002}, abstract = {In this paper, we discuss the viscosity solutions of the weakly coupled systems of fully nonlinear second order degenerate parabolic equations and their Cauchy-Dirichlet problem. We prove the existence, uniqueness and continuity of viscosity solution by combining Perron's method with the technique of coupled solutions. The results here generalize those in [2] and [3].}, language = {en} } @unpublished{SchroheSeiler2002, author = {Schrohe, Elmar and Seiler, J{\"o}rg}, title = {The resolvent of closed extensions of cone differential operators}, url =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conical degeneracy and establish maximal regularity for the Cauchy problem u - Δu = f, u(0) = 0.}, language = {en} } @unpublished{NazaikinskiiSchulzeSternin2002, author = {Nazaikinskii, Vladimir and Schulze, Bert-Wolfgang and Sternin, Boris}, title = {Surgery and the relative index theorem for families of elliptic operators}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26300}, year = {2002}, abstract = {We prove a theorem describing the behaviour of the relative index of families of Fredholm operators under surgery performed on spaces where the operators act. In connection with additional conditions (like symmetry conditions) this theorem results in index formulas for given operator families. By way of an example, we give an application to index theory of families of boundary value problems.}, language = {en} } @unpublished{NazaikinskiiSternin2002, author = {Nazaikinskii, Vladimir and Sternin, Boris}, title = {Relative elliptic theory}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26400}, year = {2002}, abstract = {This paper is a survey of relative elliptic theory (i.e. elliptic theory in the category of smooth embeddings), closely related to the Sobolev problem, first studied by Sternin in the 1960s. We consider both analytic aspects to the theory (the structure of the algebra of morphismus, ellipticity, Fredholm property) and topological aspects (index formulas and Riemann-Roch theorems). We also study the algebra of Green operators arising as a subalgebra of the algebra of morphisms.}, language = {en} } @unpublished{HarutjunjanSchulze2002, author = {Harutjunjan, G. and Schulze, Bert-Wolfgang}, title = {Reduction of orders in boundary value problems without the transmission property}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26220}, year = {2002}, abstract = {Given an algebra of pseudo-differential operators on a manifold, an elliptic element is said to be a reduction of orders, if it induces isomorphisms of Sobolev spaces with a corresponding shift of smoothness. Reductions of orders on a manifold with boundary refer to boundary value problems. We consider smooth symbols and ellipticity without additional boundary conditions which is the relevant case on a manifold with boundary. Starting from a class of symbols that has been investigated before for integer orders in boundary value problems with the transmission property we study operators of arbitrary real orders that play a similar role for operators without the transmission property. Moreover, we show that order reducing symbols have the Volterra property and are parabolic of anisotropy 1; analogous relations are formulated for arbitrary anisotropies. We finally investigate parameter-dependent operators, apply a kernel cut-off construction with respect to the parameter and show that corresponding holomorphic operator-valued Mellin symbols reduce orders in weighted Sobolev spaces on a cone with boundary.}, language = {en} } @unpublished{XiaochunWitt2002, author = {Xiaochun, Liu and Witt, Ingo}, title = {Pseudodifferential calculi on the half-line respecting prescribed asymptotic types}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26255}, year = {2002}, abstract = {Contents: 1. Introduction 2. Preliminaries 3. Basic Elements of the Calculus 4. Further Elements of the Calculus}, language = {en} } @unpublished{SchulzeSeiler2002, author = {Schulze, Bert-Wolfgang and Seiler, J{\"o}rg}, title = {Pseudodifferential boundary value problems with global projection conditions}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26233}, year = {2002}, abstract = {Contents: Introduction 1 Operators with the transmission property 1.1 Operators on a manifold with boundary 1.2 Conditions with pseudodifferential projections 1.3 Projections and Fredholm families 2 Boundary value problems not requiring the transmission property 2.1 Interior operators 2.2 Edge amplitude functions 2.3 Boundary value problems 3 Operators with global projection conditions 3.1 Construction for boundary symbols 3.2 Ellipticity of boundary value problems with projection data 3.3 Operators of order zero}, language = {en} } @unpublished{OliaroSchulze2002, author = {Oliaro, Alessandro and Schulze, Bert-Wolfgang}, title = {Parameter-dependent boundary value problems on manifolds with edges}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26424}, year = {2002}, abstract = {As is known from Kondratyev's work, boundary value problems for elliptic operators on a manifold with conical singularities and boundary are controlled by a principal symbolic hierarchy, where the conormal symbols belong to the typical new components, compared with the smooth case, with interior and boundary symbols. A similar picture may be expected on manifolds with corners when the base of the cone itself is a manifold with conical or edge singularities. This is a natural situation in a number of applications, though with essential new difficulties. We investigate here corresponding conormal symbols in terms of a calculus of holomorphic parameter-dependent edge boundary value problems on the base. We show that a certain kernel cut-off procedure generates all such holomorphic families, modulo smoothing elements, and we establish conormal symbols as an algebra as is necessary for a parametrix constructions in the elliptic case.}, language = {en} } @unpublished{Krainer2002, author = {Krainer, Thomas}, title = {On the inverse of parabolic boundary value problems for large times}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26310}, year = {2002}, abstract = {We construct algebras of Volterra pseudodifferential operators that contain, in particular, the inverses of the most natural classical systems of parabolic boundary value problems of general form. Parabolicity is determined by the invertibility of the principal symbols, and as a result is equivalent to the invertibility of the operators within the calculus. Existence, uniqueness, regularity, and asymptotics of solutions as t → ∞ are consquences of the mapping properties of the operators in exponentially weighted Sobolev spaces and subspaces with asymptotics. An important aspect of this work is that the microlocal and global kernel structure of the inverse operator (solution operator) of a parabolic boundary value problem for large times is clarified. Moreover, our approach naturally yields qualitative pertubation results for the solvability theory of parabolic boundary value problems. To achieve these results, we assign t = ∞ the meaning of a conical point and treat the operators as totally characteristic pseudodifferential boundary value problems.}, language = {en} } @unpublished{Davis2002, author = {Davis, Simon}, title = {On the existence of a non-zero lower bound for the number of Goldbach partitions of an even integer}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-26474}, year = {2002}, abstract = {The Goldbach partitions of an even number greater than 2, given by the sums of two prime addends, form the non-empty set for all integers 2n with 2 ≤ n ≤ 2 × 1014. It will be shown how to determine by the method of induction the existence of a non-zero lower bound for the number of Goldbach partitions of all even integers greater than or equal to 4. The proof depends on contour arguments for complex functions in the unit disk.}, language = {en} }